Solve the following pair by substitution and cross MULTIPLICATION...I)

1.	Solve the following pair by substitution and cross MULTIPLICATION...I)8x+5y=9,3x+2y=7
Answer» $\huge\red{\tt{\underline{Solution:-}}}$ 8x +5y =9 Subtract 8x both sides we GET 5y = 9 – 8x Divide by 5 Y = (9 – 8 x)/5 …(3) Plug this value of y in equation second we get 3x +2y =4 3x + 2(9 – 8 x)/5) = 4 Multiply by 5 we get 15 x + 18 - 16 x = 20 -x = 2 X = - 2 Plug this value BACK in equation (3) we get Y = (9- 8(-2))/5 Y = 25/5 Y = 5 Answer is x = -2 and y = 5 Cross multiplication method 8x +5y =9 …(1) Subtract 9 both side we get 8x +5y – 9 = 0 3x +2y =4 …(2) Subtract 4 both side we get 3x + 2y – 4 = 0 Compare with we get a1 = 8 , b1 = 5 , and c1 = -9 a2 = 3 , b2 = 2 and c2 = -4 Use the formula of cross multiplication We get x = -2 and y = 5

Solve the following pair by substitution and cross MULTIPLICATION...I)8x+5y=9,3x+2y=7

Answer»

$\huge\red{\tt{\underline{Solution:-}}}$

8x +5y =9

Subtract 8x both sides we GET

5y = 9 – 8x

Divide by 5

Y = (9 – 8 x)/5 …(3)

Plug this value of y in equation second we get

3x +2y =4

3x + 2(9 – 8 x)/5) = 4

Multiply by 5 we get

15 x + 18 - 16 x = 20

-x = 2

X = - 2

Plug this value BACK in equation (3) we get

Y = (9- 8(-2))/5

Y = 25/5

Y = 5

Answer is x = -2 and y = 5

Cross multiplication method

8x +5y =9 …(1)

Subtract 9 both side we get

8x +5y – 9 = 0

3x +2y =4 …(2)

Subtract 4 both side we get

3x + 2y – 4 = 0

Compare with

we get

a1 = 8 , b1 = 5 , and c1 = -9

a2 = 3 , b2 = 2 and c2 = -4

Use the formula of cross multiplication

We get

x = -2 and y = 5