A few days ago
Loki

math homework help?

(square root)2x+5 =x+1, solve and check solution

solve and check solution: (square root)3x-2=(square root)x-2 +2

Top 3 Answers
A few days ago
sdatary

Favorite Answer

The exact position of the square root makes a huge difference in these problems. The way you’ve translated these problems into Y! answers isn’t very clear. When you ask for help online, you should use parentheses as I did below to clarify what the square root is over – otherwise we’ll be solving the wrong problem and the solution will do you no good.

In the first problem, I’m going to assume that the square root is over the entire left side of the equation and not just the “2x”.

sqrt(2x+5) = x+1

2x+5 = (x+1)^2………………. (square both sides)

2x + 5 = x^2 + 2x + 1………. (multiply out the right side)

5 = x^2 + 1…………………….. (subtract 2x from both sides)

0 = x^2 – 4…………………….. (subtract 5 from each side)

x = 2 or -2…………………. (solve w/quadratic eq. or factors method)

To check the solution, plug 2 into the original equation and solve both sides (showing that you get 3 on both sides of the equation). Then plug -2 into the original equation and solve both sides (showing that you get different numbers on either side)… -2 is not a valid solution

For the second problem, I’m going to assume the first square root is over the entire left side, and the second is just over “x-2”

sqrt(3x-2) = sqrt(x-2) +2

3x-2 = (sqrt(x-2) + 2)^2…………. (square both sides)

3x-2 = x + (4 * sqrt(x-2)) + 2 …. (multiply out the right side)

3x – 4 = x + (4 * sqrt(x-2))……… (subtract 2 from both sides)

2x – 4 = 4 * sqrt (x-2)……………. (subtract x from both sides)

x-2 = 2 * sqrt(x-2)…………………. (divide both sides by 2)

(x-2)^2 = 4(x-2)……………………. (square both sides)

x^2 – 4x +4 = 4x – 8………………. (multiply out both sides)

x^2 – 8x +4 = -8……………………. (subtract 4x from both sides)

x^2 – 8x + 12 = 0………………….. (add 8 to both sides)

x = 6 or 2…………… (solve using quadratic or factors method)

Again, to check, plug both answers into the original equation as you did above to make sure that you get a true equation. Disregard an answer if it doesn’t check out.

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A few days ago
Varshita
sqrt (2x+5) = x+1

squaring both sides, we get

2x + 5 = (x+1)^2

2x + 5= x^2 + 2x + 1

x^2 – 4 = 0

(x-2) (x+2) = 0 [ using a^2 – a^2 = a-b x a+b]

x = 2, x = -2

Checking for x = 2

sqrt (2x+5) = x+1

substituting x = 2, we get

LHS: sqrt (2×2) +5 = sqrt (4 +5) = sqrt 9 = 3

RHS: 2 +1 = 3

Since LHS = RHS,

we can say that x = 2 is the solution to the equation sqrt (2x+5) = x+1

Checking for x = -2

sqrt (2x+5) = x+1

Substituting x = -2, we get

LHS: sqrt [(2x-2) + 5] = sqrt (-4 +5) = sqrt 1 = 1

RHS: -2 + 1 = -1

Since LHS is NOT equal to RHS,

therefore x = -2 is not the solution for the equation sqrt (2x+5) = x+1

FOr question 2… can u plz clearly mention what part is under square root.?

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A few days ago
Anonymous
2x+5=(x+1)(x+1)

solution: x=2 or -2

The second one is equal to

x-2=2*(square root)x-2

or

3x¤2 -12x+12=0

with the only one solution x=2

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