Question

Give first the step you will use to separate the variable and then solve the equation:
(a) 3l = 42
(b) $\frac{b}{2}$= 6
(c) $\frac{p}{7}$ = 4
(d) 4x = 25
(e) 8y = 36
(f) $\frac{z}{3}$=$\frac{5}{4}$
(g) $\frac{a}{5}$=$\frac{7}{15}$
(h) 20t = – 10

Answer 1

(a) $3l=42$
\Rightarrow$$\frac{3l}{3}=\frac{42}{3}
$\Rightarrow l=14$ [Dividing both sides by 3]

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(b) $\frac{b}{2}=6$
$\Rightarrow \frac{b}{2}\times2=6\times 2$
$\Rightarrow b=12$

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(c) $\frac{p}{7}=4$
$\Rightarrow \frac{p}{7}\times 7=4\times7$
$\Rightarrow p=28$

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(d) $4x=25$
$\Rightarrow \frac{4x}{4}=\frac{25}{4}$
$\Rightarrow x=\frac{25}{4}$

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(e) 8y = 36
$\Rightarrow\frac{8y}{8}=\frac{36}{8}$
(f) $\frac{z}{3}=\frac{5}{4}$
\Rightarrow$$\frac{a}{5}\times5=\frac{7}{15}\times 5
$\Rightarrow z=\frac{7}{3}$

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(g) $\frac{a}{5}$=$\frac{7}{15}$
$\Rightarrow \frac{a}{5}\times 5=\frac{7}{15}\times 5$

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$(h)\,20t=-10$
$\Rightarrow \frac{20t}{20}=\frac{-10}{20}$
$\Rightarrow t=\frac{-1}{2}$