Question

0.3x＋7x-0.25x=21.5

Answer 1

(1) 0.3x+7x-0.25x=21.5

(0.3+7-0.25)x=21.5

7.05x=21.5

x=141/430

(2) 8.7*(36-x)=0

31.2-8.7x=0

31.2=8.7x

x=312/87

(3) 4x*(x+0.2)=1.2