y = 40 + (x - 600)*0.35

y = 50 + (x - 600)*0.10

what are the steps to get the answer

1 answer

40 + ( x - 600 ) * 0.35 = 50 + ( x - 600 ) * 0.1

40 + 0.35 x - 600 * 0.35 = 50 + 0.1 x - 600 * 0.1

40 + 0.35 x - 210 = 50 + 0.1 x - 60

0.35 x - 170 = 0.1 x - 10

0.35 x - 0. 1 x = - 10 + 170

0.25 x = 160 Divide both sides by 0.25

x = 160 / 0.25 = 160 * 4

x = 640

Remark :

Dividing by 0.25 is equal to multiply by 4 becouse

1 / 0.25 = 4