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

AcademicMathematicsNCERTClass 7

To do:

We have to give first the step we will use to separate the variable and then solve the equation.

Solution:

 (a) $3l=42$

Divide both the sides by 3 we get,

$\frac{3l}{3}=\frac{42}{3}$

$l=14$

(b) $\frac{b}{2}=6$

Multiplying both sides by 2 we get,

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

$b=12$

(c) $\frac{p}{7}=4$

Multiplying both sides by 7 we get,

$(\frac{p}{7})\times 7=4\times 7$

$p=28$

(d) $4x=25$

Dividing both the sides by 4 we get,

$\frac{4x}{4}=\frac{25}{4}$

$x=\frac{25}{4}$

(e) $8y=36$

Dividing both the sides by 8 we get,

$\frac{8y}{8}=\frac{36}{8}$

$y=\frac{9}{2}$

(f) $\frac{z}{3}=\frac{5}{4}$

Multiplying both sides by 3 we get,

$(\frac{z}{3})\times 3=(\frac{5}{4})\times 3$

$z=\frac{15}{4}$

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

Multiplying both sides by 5 we get,

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

$a=\frac{7}{3}$

(h) $20t=-10$

Dividing both sides by 20 we get,

$\frac{20t}{20}=\frac{-10}{20}$

$t=\frac{-1}{2}$

raja
Updated on 10-Oct-2022 13:33:38

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