326 Review Questions and Answers
That’s in the form we want! Again from Answer 15-4, the slope-intercept form of the equation
for line QR is
y= (5/2)x− 1
When we multiply each side by 2, we get
2 y= 5 x− 2
Subtracting 5x from each side, we obtain
− 5 x+ 2 y=− 2
That’s in the form we want! Once again referring to Answer 15-4, the slope-intercept form of
the equation for line PR is
y=x+ 2
Subtracting x from each side gives us
−x+y= 2
That’s in the form we want!
Chapter 16
Question 16-1
In Chap. 16, we learned how a two-by-two linear system in variables x and y can be solved by
the following process:
- Morph both equations into SI form with y all by itself on the left side of the
equals sign. - Mix the two equations to get a first-degree equation in x.
- Solve the first-degree equation for x.
- Substitute that solution back into one of the SI equations to solve for y.
How can we solve such a system by morphing and mixing alone, without substituting either
variable for the other?
Answer 16-1
We can go through the morph-and-mix process twice, first for one variable and then for the
other. We proceed like this:
- Morph both equations into SI form with y all by itself on the left side of the
equals sign. - Mix the two equations to get a first-degree equation in x.