Question

Solve each of the following equations and also check your results in each case:

(xvi) $0.18(5x-4)=0.5x+0.8$

Answer 1

Given: $0.18(5x-4)=0.5x+0.8$

$0.18(5x-4)-0.5x=0.8$

$0.90x-0.72-0.5x=0.8$

$0.90x-0.5x=0.8+0.72$

$0.40x=1.52$

$x=\frac{1.52}{0.40}$

$\therefore x=3.8$

To check $0.18(5x-4)=0.5x+0.8forx=3.8$

L.H.S. = 0.18(5x-4)
=0.18[5(3.8)-4]
=0.18(19-4)
= 2.7

R.H.S. = 0.5x + 0.8
= 0.5(3.8) + 0.8
= 1.9 + 0.8
= 2.7
$\therefore$ L.H.S. = R.H.S.

Hence, the given equation is verified for x = 3.8.