Question

answer me the question of d), e), f), in picture given.​

Answer 1

Answer:

D)

Let Haris age be x

His grandfather's age 10x

also given hari is 63 years younger than his grandfather

therefore the equation is

10x-63=x

10x-x=63

9x=63

x=63/9

x=7

therefore age of

Hari=x= 7 years

His Grandfather= 10x=10×7=70 years

also difference is 63

e) Let the number be x

We have to form an equation from the data

$\frac{1}{4} \times x = 2x - 7 \\ \frac{x}{4} = 2x - 7 \\ \frac{x}{4} + 7 = 2x \\ \frac{x + 28}{4} = 2x \\ x + 28 = 2x \times 4 = 8x$

Subtracting x from both sides,that is

$28 = 7x \\ x = \frac{28}{7} \\ x = 4$

therefore the number is 4

Let's check whether it's correct or not

$\frac{1}{4} \times 4 = 2 \times 4 - 7\\ 1 = 8 - 7 \\ 1 = 1$

L.H.S=R.H.S

hence verified

f)

To find n

if m=5

$\frac{5}{2}mn = 18 + mn \\ \frac{5}{2} \times 5 \times n = 18 + 5 \times n \\ \frac{25n}{2} = 18 + 5n \\ 25n = 2(18 + 5n) \\ 25n = 36 + 10n \\ 25n - 10n = 36 \\ 15n = 36 \\ n = \frac{36}{15} \\ n = \frac{12}{5}$

Let's check whether it's correct or not

$\frac{5}{2} \times 5 \times \frac{12}{5} = 18 + 5 \times \frac{12}{5} \\ 5 \times 6 = 18 + 12 \\ 30 = 30$

L.H.S=R.H.S

hence verified

hope it helps