Question

Which is the approximate solution for the system of equations 3x+4y=2 and 4x+y=-4


A(-1.4,1.5)
B(1.4,1.5)
C(0.9,-0.2)
D(-0.9-0.2)

Answer 1

$3x+4y=2\qquad\text{subtract 3x from both sides}\\\\4y=-3x+2\qquad\text{divide both sides by 4}\\\\y=-\dfrac{3}{4}x+\dfrac{2}{4}\to y=-\dfrac{3}{4}x+\dfrac{1}{2}\\\\for\ x=0\to y=-\dfrac{3}{4}(0)+\dfrac{1}{2}=0+\dfrac{1}{2}=\dfrac{1}{2}\to\left(0,\ \dfrac{1}{2}\right)\\\\for\ x=2\to y=-\dfrac{3}{4}(2)+\dfrac{1}{2}=-\dfrac{3}{2}+\dfrac{1}{2}=-\dfrac{2}{2}=-1\to(2,\ -1)\\--------------------------------$

$4x+y=-4\qquad\text{subtract 4x from both sides}\\\\y=-4x-4\\\\for\ x=0\to y=-4(0)-4=0-4=-4\to(0,\ -4)\\\\for\ x=-1\to y=-4(-1)-4=4-4=0\to(-1,\ 0)\\\\Answer:\ \boxed{A.\ (-1.4,\ 1.5)}$

Answer 2

The approximate solution for the system of equations 3x + 4y = 2 and 4x + y = –4 will be (–1.4, 1.5). Then the correct option is A.

What is the solution of the equation?

The solution of the equation means the value of the unknown or variable.

The equations are given below.

3x + 4y = 2      …1

4x + y = -4       …2

From equation 2, we have

y = –4 – 4x

Put in equation 1, we have

3x + 4(–4 – 4x) = 2

3x – 16x – 16 = 2

–13x = 18

x = –18/13

x = –1.38

x ≈ –1.4

Then the value of y will be

y = –4 – 4(–1.38)

y = 1.52

y ≈ 1.5

Then the correct option is A.

More about the solution of the equation link is given below.

https://brainly.com/question/545403

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