Question

Simplify and solve for x. ​ ​ 5(x+20)= 7x+30

Answer 1

Answer:

x = 35

Step-by-step explanation:

Solve for x:

5 (x + 20) = 7 x + 30

Expand out terms of the left hand side:

5 x + 100 = 7 x + 30

Subtract 7 x from both sides:

(5 x - 7 x) + 100 = (7 x - 7 x) + 30

5 x - 7 x = -2 x:

-2 x + 100 = (7 x - 7 x) + 30

7 x - 7 x = 0:

100 - 2 x = 30

Subtract 100 from both sides:

(100 - 100) - 2 x = 30 - 100

100 - 100 = 0:

-2 x = 30 - 100

30 - 100 = -70:

-2 x = -70

Divide both sides of -2 x = -70 by -2:

(-2 x)/(-2) = (-70)/(-2)

(-2)/(-2) = 1:

x = (-70)/(-2)

The gcd of -70 and -2 is -2, so (-70)/(-2) = (-2×35)/(-2×1) = (-2)/(-2)×35 = 35:

Answer: x = 35

Answer 2

Answer:

x =  35

Step-by-step explanation:

5(x+20)= 7x+30

5x + 100 = 7x + 30

-30                   -30

5x + 70 = 7x

-5x          -5x

70 = 2x

/2      /2

35 = x