(-5)x+7=42

Subtract 7 from both sides of the equation

(-5)x = 35

Divide both sides of the equation by -5

x= -7

The answer is -7

Subtract the 7 from both sides

-5x + 7 – 7 = 42 – 7

-5x = 35

Divide 35 by -5

-5x/-5 = 35/-5

x = -7

Good luck and hope this helps!

substitute each of the values for x and see if the expression is true;

in this case -5(-7) +7=42

minus times a minus is a PLUS, so

PLUS 35 plus 7=42 ? yes it does, now check the others to prove only one answer is correct:

for value 7, it equals -35+7=MINUS 28

for value 21 it equals -105+7=MINUS 98

for value -21 it equals 105+7=PLUS 112

-5x+7=42

-5x=35

-7=x

-7 -7

-5x=35

/-5 /-5

x=-7

so x=-7

x = -7