# Math Help - Linear Equation Help

1. ## Linear Equation Help

Hey everybody, i really need some help quick.

Im having trouble with linear equations. If anyone can show me how to solve them that would be great.

3x + 5y = 26
2x - y = 13

x - 2y = -12
3x + 8y = 34

I also need help on these.

2x - 3y = 4
.02x + .01y = .52

Last but not least...

Terry did all 25 problems on the test and got an 85. Scores are computed by giving 4 points for each right answer and subtracting 1 point for each wrong answer. How many problems did Terry get right and wrong?

Varibles:

Equation:

2. Originally Posted by misfitgirl16
Hey everybody, i really need some help quick.

Im having trouble with linear equations. If anyone can show me how to solve them that would be great.

3x + 5y = 26
2x - y = 13
In second equation solve for 'y':
y=-13+2x
Subsitute into first,
3x+5(-13+2x)=26
3x-65+10x=26
13x-65=26
13x=91
x=7
Thus,
y=-13+2(7)=-13+14=1

3. Originally Posted by misfitgirl16
x - 2y = -12
3x + 8y = 34
In first solve for 'x':
$x=2y-12$
Substitute into second,
$3(2y-12)+8y=34$
$6y-36+8y=34$
$14y-36=34$
$14y=70$
$y=5$
Thus,
$x=2y-12=2(5)-12=10-12=-2$

4. Thank you so much! i appreciate it