Question

please solve them class 10 linear equations both 12 a and b​

Answer 1

Answer:

Question

Seven times a two-digit number is equal to four times the number obtained by reversing the digits. If the difference between the digits is 3. Find the number.

Solution

Assume the ones digit as x and tens digit as y.

so number formed = 10y+x

Number obtained after reversing the digits = 10x+y

$\bold \purple{ \underline {\sf{according \: to \: the \: question}}}$

$\to \: 7(10y + x) = 4(10x + y) \\ \\ \to \: 70y + 7x = 40x + 4y \\ \\ \to66y = 33x \\ \\ \to \: \bold{ 2y - x = 0 }\: \: \: \: \: . ....(i) \\ \to \bold{ \: x - y = 3} \: \: \: \: \: \: \: \: \: \: \: ......(ii)$

$\bold \purple{ \sf{solve \: the \: equations}}$

y = 3

from equation (ii) we will find the equation of x

x= 6

therefore the number is 36.

________________________

Question

The sum of a two digit number and the number obtained by reversing the order of its digits is 99. If the digits differ by 3, find the number.

Solution

Assume the ones digit as x and tens digit as y.

so number formed = 10y+x

Number obtained after reversing the digits = 10x+y

$\bold \orange{ \underline {\sf{according \: to \: the \: question}}}$

10y+ x+ 10x+ y= 99

11x + 11y= 99

x+y = 9 .......(i)

x-y= 3 ........(ii)

$\bold \orange{ \sf{solve \: the \: equations}}$

$\bold{\to \: value \: of \: x = 6}\\ </p><p> \to \bold{\: value \: of \: y=3}$

________________________

Answer 2

Question

Seven times a two-digit number is equal to four times the number obtained by reversing the digits. If the difference between the digits is 3. Find the number.

Solution

Assume the ones digit as x and tens digit as y.

so number formed = 10y+x

Number obtained after reversing the digits = 10x+y

$→7(10y+x)=4(10x+y)→70y+7x=40x+4y→66y=33x→2y−x=0.....(i)→x−y=3......(ii)</p><p>$

y = 3

from equation (ii) we will find the equation of x

x= 6

therefore the number is 36.

________________________

Question

The sum of a two digit number and the number obtained by reversing the order of its digits is 99. If the digits differ by 3, find the number.

Solution

Assume the ones digit as x and tens digit as y.

so number formed = 10y+x

Number obtained after reversing the digits = 10x+y

10y+ x+ 10x+ y= 99

11x + 11y= 99

x+y = 9 .......(i)

x-y= 3 ........(ii)