Robert S. answered • 07/02/15

Tutor

New to Wyzant
Rice Univ. Grad Tutor for Chemistry, Physics, and Algebra to Calculus

Part A: In order to distinguish the two line, make the Y in (formula of) the first line a Y

_{1}and the other Y_{2}.Y

_{1}= -x +2Y

_{2}= 4x +3Now when the two lines intersect the values for the Y's at that point must be equal. So

-x +2 = Y

_{1}= Y_{2}= 4x +3Part B: What? Make tables? Doesn't you teacher know algebra?

-x +2 = 4x +3

Isolate the x's

2-3 = 4x +x

-1 = 5x

x = -1/5 = - 0.2 ==> Y

_{1}= Y_{2}= -(-0.2) + 2 = 2.2**So the lines should intersect at the point (-0.2, 2.2)**

Part C: To do this (easily) put both equations in slope-(y)intercept form. y = mx +b

In this form m= the slope (rise/run) and b= the y-intercept = the point on the y-axis where the line crosses the y-axis.

So for Y

_{1}= -x +2 , put a little mark on the vertical (Y) axis at +2,now from that point, count 2 (unit spaces) to the

**right**, then from there count**down**2 spaces and put a little mark.Now connecting those 2 points draws the first line.

For Y

_{2}= 4x+3, find 3 units**up**on the y-axis (mark), now from there move to the**right**3 units,From there

**move up**12 spaces and put a mark. I used 3 and 12 because m=4=12/3. Now connect the two marks to draw the second line.**Again, the lines should intersect at the point (-0.2, 2.2)**