Question

Solve and check the solution in the following equation.
1. $x+7=9$
2.$\frac{x}{4}=25$
3.$9y=-135$
4.$15-x=4$
5.$3(x-3)=15$
6.$7y+3=9$

Answer 1

(i) $x+7=9$ ……..$\left(1\right)$

$x=9-7=2$

Using equation $\left(1\right)$ $[x=2]$

Check $\Rightarrow 2+7=9$ (Proved).

(ii) $\frac{x}{4}=25$ ……..$\left(1\right)$

$x=4\times 25=100$

Check: $\frac{200}{4}=25$ (Proved).

(iii) $4y=-135$ ………$\left(1\right)$

$y=-\frac{135}{9}=-15$

Check $=9\times (-15)=-135$ (Proved).

(iv) $15-x=4$ ……….$\left(1\right)$

$x=15-4=11$

Check $15-11=4$ (Proved)

(v) $3(x-3)=15$ ………..$\left(1\right)$

$3x-9=15$

$3x=9+5$

$3x=24$

$x=24=8$

Check: $3(8-3)=3\left(5\right)=15$ (Proved).

(vi) $7y+3=9$

$7y=4-3$

$7y=6$

$y=\frac{6}{7}$

Check $7\times \frac{6}{7}+3=9$ (Proved).