Solve the following equations:
$(a).\ 2(x+4)=12$
$(b).\ 3(n-5)=21$
$(c).\ 3(n-5)=-21$
$(d).\ -4(2+x)=8$
$(e).\ 4(2-x)=8$

AcademicMathematicsNCERTClass 7

To do:

We have to solve the given equations.

Solution:

(a) $2(x+4)=12$

$\Rightarrow 2x+8=12$

$\Rightarrow 2x=12-8$

$\Rightarrow 2x=4$

$\Rightarrow x=\frac{4}{2}$

$\Rightarrow x=2$

(b) $3(n-5)=21$

$3n-15=21$

$\Rightarrow 3n=21+15$

$\Rightarrow 3n=36$

$\Rightarrow n=\frac{36}{3}$

$\Rightarrow n=12$

(c) $3(n-5)=-21$

$\Rightarrow 3n-15=-21$

$\Rightarrow 3n=-21+15$

$\Rightarrow 3n=-6$

$\Rightarrow n=\frac{-6}{3}$

$\Rightarrow n=-2$

(d) $-4(2+x)=8$

$\Rightarrow -8-4x=8$

$\Rightarrow -4x=8+8$

$\Rightarrow -4x=16$

$\Rightarrow x=\frac{-16}{4}$

$\Rightarrow x=-4$

(e) $4(2-x)=8$

$\Rightarrow 8-4x=8$

$\Rightarrow -4x=8-8$

$\Rightarrow -4x=0$

$\Rightarrow x=0$

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

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