Question

0.4(0.5a+7)=1.2−0.2a pls give answer with explanation answer =marked heart ,5star and brainliest ​

Answer 1

Answer:

your answer is -4

Step-by-step explanation:

firstly we will mupltiply in bracket (0.5a+7) with 4

=0.4(0.5a+7)=1.2-0.2a

when we multiplying we get,

=0.20a+2.8=1.2-0.2a

we arrange in suitable group

= 0.20a+0.2a= 1.2-2.8

when we grouping the sign will change when + is the sign change into - and when × is the sign will change into ÷ and when it is ÷ it is × and when - is it is +

then add 0.20a+0.2a=1.2+(-2.8)

=0.4a=-1.6

= a= -1.6/0.4

decimal will remove then we get

= a= -16/4

= a= -4

It will help you

THANK YOU

Answer 2

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Let 0.2x+0.3y=1.3 ....(1)

0.4x+0.5y=2.3 ....(2)

Multiply eqn(1) by 10 we get

2x+3y=13 ....(3)

Multiply eqn(2) by 10 we get

4x+5y=23 ....(4)

Solving equations (3) and (4)

5×(3)⇒10x+15y=65

3×(4)⇒12x+15y=69

Subtracting we get 12x+15y−10x−15y=69−65=4

or 2x=4 or x=2

Substituting x=2 in eqn(3) we get

2x+3y=13⇒2×2+3y=13 or 3y=13−4=9 or y=3

Hence x=2,y=3