Question

answer these all question step by sstep class7​

Answer 1

Answer:

i'll do the first 3 questions for you

Step-by-step explanation:

11. 3x - 12 = x + 8

3x - x = 8 +12

2x = 20

Move 2 to RHS and divide

x = 10

12. Let the age of B be x

A's age = 5x

B's age = x

A's age 10 years later  =5x + 10

B's age 10 years later  = x + 10  

Then, 5x, +10 = 3 x + 10

5x + 10 = 3x + 30

Swamp LHS with RHS

2x = 20

Bring 2 to RHS and divide

x = 10

A's age = 5x = 5 x 10 = 50years

B's age = 10years

13. Let the share of B be x

Share of A = x + 70

Share of = x + 80

Since the varibles and numericals are same;

x +70 and 80 = x + 150

Group all the x's

70 + 150 = 220

So we should get, 3x + 220 = 640

Move 220 to RHS

640 - 220

3x = 420

move 3 to RHS and divide

x = 140

Share of B = 140 + 70 = 210 Rs.

Hope this helps