Question

0.3a+0.5=0.4a-0.2 solve for a

Answer 1

$0.3a + 0.5 = 0.4a - 0.2 \\ \\ 0.5 + 0.2 = 0.4a - 0.3a \\ \\ 0.7 = a(0.4 - 0.3) \\ \\ 0.7 = a(0.1) \\ \\ a = \frac{0.7}{0.1} \\ \\ a = 7$
hope this helps.....

Answer 2

0.3 a + 0.5 = 0.4 a - 0.2

0.5 + 0.2 = 0.4 a - 0.3 a

0.7 = 0.1 a

Multiply by 10 on both sides,

0.7 × 10 = 0.1 a × 10

7 = a

Therefore the value of a is 7 .

$\:$