Question

3x+2y=11.2x-3y=-10 using method elimination by substitute​

Answer 1

Answer:

hii

Step-by-step explanation:

(i) 2x – 3y = 7 … (1) 5x + y = 9 … (2) Step (1) From the equation (2) 5x + y = 9 y = -5x + 9 Step (2) Substitute (3) in (1) 2x – 3(-5x + 9) = 7 2x + 15x – 27 = 7 17x = 7 + 27 17x = 34 x = 34173417 = 2; x = 2 Step (3) Substitute x = 2 in (3) y = – 5(2) + 9 = -10 + 9 = -1 Solution: x = 2; y = -1 (ii) 1.5x + 0.1y = 6.2 … (1) 3x – 0.1y = 11.2 … (2) Multiply (1 ) x 10 15x + y = 62 … (3) (2) x 10 ⇒ 30x – 4y = 112 … (4) Step (1) From equation (3) 15x + y = 62 y = -15x + 62 … (5) Step (2) Substitute (5) in (4) 30x – 4 (-15x + 62) = 112 30x + 60x – 248 = 112 90x = 112 + 248 90x = 360 x = 3609036090 x = 4 Step (3) Substitute x = 4 in (5) y = -15(4) + 62 = -60 + 62 y = 2 Solution: x = 4; y = 2 (iii) 10% of x + 20% of y = 24; 3x – y = 20 x + 2y = 240 … (1) 3x – y =20 … (2) Step (1) From equation (2) 3x – y = 20 -y = 20 – 3x y = 3x – 20 — (3) Step (2) Substitute (3) in (1) x + 2(3x – 20) = 240 x + 6x – 40 = 240 7x = 240 + 40 x = 28072807 x = 40 Step (3) Substitute x = 40 in (3) y = 3 (40) – 20 = 120 – 20 = 100 Solution : x = 40 and y = 100 (iv) √2x - √3y = 1 ... (1) √3x - √8y = 0 ... (2) Step (1) From the equation (2) Step (2) Substitute (3) in (1) √2x - √3y = 1 Step (3) Substitute x = √8 in (1) Solution: x = √8 and y = √3Read more on Sarthaks.com - https://www.sarthaks.com/965804/solve-using-the-method-of-substitution-i-2x-3y-7-5x-y-9-ii-1-5x-0-1y-6-2-3x-0-4y-11-2?show=965879#a965879

Answer 2

Answer:

Step-by-step explanation: 3x + 2y= 11 ------ 1

                                            2x - 3y = -10 ------ 2

eq 2 x 3 and eq 1 x 2

6x + 4y = 22

-6x + 9y = 30

      13y = 52

y= 52/13= 4

substitute y in eq 1

3x + 2(4) = 11

3x +8 = 11

3x= 11-8 =3

x= 3/3= 1

Therefore, x= 1 and y= 4!!

Hope this helps!