Question

Consider the system of equations:
3
4
x
+
5
12
y
=
1
6

−
2.5
x
+
1.25
y
=
6.25
Is the ordered pair
(
−
4
5
,
6
5
)
a solution to this system?
Select one answer
A
Yes, because it satisfies the first equation when substituted.

B
Yes, because it satisfies the second equation when substituted.

C
Yes, because it satisfies both equations when substituted.

D
No, because it does not satisfy either equation when substituted.

Answer 1

D

Substitute x = −4/5, y = 6/5.

First equation: (3/4)(−4/5) + (5/12)(6/5) = −3/5 + 1/2 = −0.6 + 0.5 = −0.1 ≠ 1/6.

Second equation: −2.5(−4/5) + 1.25(6/5) = 2.0 + 1.5 = 3.5 ≠ 6.25.

So the pair satisfies neither equation.