Q:

A line that includes the points (-10, 3) and (-9, g) has a slope of 7. What is the value of g?​

Accepted Solution

A:
Answer:
g
=
7

Explanation:
Single value slope (gradient) fixes the curve as a straight line. So we are talking about the standard equation form
y
=
m
x
+
c
where
m
is the gradient.
Gradient
β†’
m
=
βˆ’
5
=
change in y-axis
change in x-axis
Let point 1 be
P
1
β†’
(
x
1
,
y
1
)
=
(
βˆ’
4
,
βˆ’
8
)

Let point 2 be
P
2
β†’
(
x
2
,
y
2
)
=
(
βˆ’
7
,
g
)
βˆ’
5
=
change in y-axis
change in x-axis
=
βˆ’
8
βˆ’
g
βˆ’
4
βˆ’
(
βˆ’
7
)
βˆ’
5
=
βˆ’
8
βˆ’
g
3
multiply both sides by 3
βˆ’
5
Γ—
3
=
(
βˆ’
8
βˆ’
g
)
Γ—
3
3
But
βˆ’
5
Γ—
3
=
βˆ’
15
and
3
3
=
1
βˆ’
15
=
βˆ’
8
βˆ’
g

←
corrected 15 to -15
Add 8 to both sides
βˆ’
7
=
βˆ’
g
Multiply both sides by (-1)
7
=
+
g
g
=
7