Question

Solve 7x – 2y = –3 14x + y = 14 a. (4,5/7) b. (4,7/5) c. (5/7,4) d. (7/5,4)

Answer 1

Answer:

The answer is the option C $(\frac{5}{7}, 4)$

Step-by-step explanation:

we have

$7x-2y=-3$ ------> equation A

$14x+y=14$ ------> equation B

Multiply by $2$ equation B

$2*(14x+y)=2*14$ ------> $28x+2y=28$ -----> equation C

Adds equation A and equation C

$7x-2y=-3\\28x+2y=28\\----------\\7x+28x=-3+28\\35x=25\\\\ x=\frac{25}{35}\\\\x=\frac{5}{7}$

Find the value of y

$14(\frac{5}{7})+y=14$

$10+y=14$

$y=14-10=4$

the solution is the point $(\frac{5}{7}, 4)$

Answer 2

7x - 2y = -3 . . . (1)
14x + y = 14 . . . (2)
(1) x 2 => 14x - 4y = -6 . . . (3)
(2) - (3) => 5y = 20
y = 20/5 = 4
From (1); 7x - 2(4) = -3
7x - 8 = -3
7x = -3 + 8 = 5
x = 5/7

Solution = (5/7, 4)