7.
two equations are given below:

a – 3b = 4
a = b – 2

what is the solution to the set of equations in the form (a, b)? (5 points)

(–2, –2)
(–3, –1)
(–9, –7)
(–5, –3)
8.
a student is trying to solve the set of two equations given below:

equation a: x + z = 6
equation b: 2x + 4z = 1

which of the following is a possible step used in eliminating the z-term? (5 points)

multiply equation b by 4.
multiply equation a by 2.
multiply equation a by –4.
multiply equation b by 2.
9.
the work of a student to solve a set of equations is shown:

equation a: y = 4 – 2z
equation b: 4y = 2 – 4z

step 1: –4(y) = –4(4 – 2z) [equation a is multiplied by –4.]
4y = 2 – 4z [equation b]
step 2: –4y = 4 – 2z [equation a in step 1 is simplified.]
4y = 2 – 4z [equation b]
step 3: 0 = 6 – 6z [equations in step 2 are added.]
step 4: 6z = 6
step 5: z = 1

in which step did the student first make an error? (5 points)

step 1
step 3
step 4
step 2
10.
variable p is 2 more than variable d. variable p is also 1 less than variable d. which pair of equations best models the relationship between p and d? (5 points)

p = d + 2
p = d – 1
p = d – 2
p = d + 1
d = 2p
d = 2p – 1
d = 2p
d = 2p + 1