Answer:
(7, - 7 )
Step-by-step explanation:
- 4x + y = - 35 → (1)
- 2x - y = - 7 → (2)
adding the 2 equations term by term will eliminate the y- term
(- 4x - 2x) + (y - y) = - 35 - 7
- 6x + 0 = - 42
- 6x = - 42 ( divide both sides by - 6 )
x = 7
substitute x = 7 into either of the 2 equations and solve for y
substituting into (1)
- 4(7) + y = - 35
- 28 + y = - 35 ( add 28 to both sides )
y = - 7
solution is (7, - 7 )
Answer:
6.5 mph
Step-by-step explanation:
Pace per mile
09 : 13.85
min : sec
Speed
0.1083 miles per minute
=
6.5 miles per hour
x
4
+
50
x
2
+
625Rewrite
625
as
25
2
.
u
2
+
50
u
+
25
2
Check the middle term by multiplying
2
a
b
and compare this result with the middle term in the original expression.
2
a
b
=
2
⋅
u
⋅
25
Simplify.
2
a
b
=
50
u
Factor using the perfect square trinomial rule
a
2
+
2
a
b
+
b
2
=
(
a
+
b
)
2
, where
a
=
u
and
b
=
25
.
(
u
+
25
)
2
Replace all occurrences of
u
with
x
2
.
(
x
2
+
25
)
2
