Answer: 40%. Alternatively, you can think about it this way. The item is 40% off. This means you'll pay 60.000% of the total cost (100% - 40% = 60.000%).
Let's solve your system by substitution.
y
=
3
x
+
5
;
y
=
x
+
19
Step: Solve
y
=
3
x
+
5
for y:
y
=
3
x
+
5
Step: Substitute
3
x
+
5
for
y
in
y
=
x
+
19
:
y
=
x
+
19
3
x
+
5
=
x
+
19
3
x
+
5
+
−
x
=
x
+
19
+
−
x
(Add -x to both sides)
2
x
+
5
=
19
2
x
+
5
+
−
5
=
19
+
−
5
(Add -5 to both sides)
2
x
=
14
2
x
2
=
14
2
(Divide both sides by 2)
x
=
7
Step: Substitute
7
for
x
in
y
=
3
x
+
5
:
y
=
3
x
+
5
y
=
(
3
)
(
7
)
+
5
y
=
26
(Simplify both sides of the equation)
Answer:
x
=
7
and
y
=
26
0.151515 (and so on) Try to stop at the third decimal when dividing on paper
