Question

Select the coordinate point that is a solution of equations. 2x+y=7; 3x-4y=5

a) (-1,9)
b) (-3,-1)
c) (7,4)
D) (3,1)
please help​

Answer 1

D(3,1)

Explanation:

The given equations are:

`2x+y=7...(1)`

and

`3x-4y=5...(2)`

Multiply equation (1) by 4.

`\Rightarrow 8x+4y=28...(3)`

Add equation (2) and (3)

`\Rightarrow 11x=33`

Divide through by 11.

`\Rightarrow x=3`

Put x=3 into equation (1)

`2(3)+y=7`

`6+y=7`

`y=7-6`

`y=1`

The solution is (3,1)

The correct choice is D

Answer 2

D (3,1)

Explanation:

solving simultaneous equations

Arrange equations

2x+y=7

3x-4y=5

make y side cancell by addition by multiplying by 4 and 1 as shown

4{2x+y=7}

1{3x-4y=5}

8x+4y=28

3x-4y=5

11x=33

x=33/11=3

substitute for x=3 in 3x-4y=5

9-4y=5

4=4y

y=1