USe the points and slope to write in y=mx+b!
Answer:
236
Step-by-step explanation:
We assume the cost is a linear function of the number of lessons. That means the slope is the same everywhere.
Let (lessons, cost) = (x, y). We have (4, 84), (8, 160), (12, y3).
(y2 -y1)/(x2 -x1) = (y3 -y2)/(x3 -x2)
(160 -84)/(8 -4) = (y3 -160)/(12 -8)
76 = y3 -160
y3 = 160 +76 = 236
The cost will be $236 for 12 lessons.
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The cost function is ...
y = 19x +8 . . . . for x lessons
Let y = ax²+bx+c then substitute all of orders. we'll be doing equations system.
Ok we are at this.
Substitute c = 3 into equation 1 and equation 3.
then addition and subtract for a-b = 3 and a+b = -1
Therefore a = -2, substitute a = -2 in a-b+c=0 or a+b+c=2 but i'm doing a-b+c=0 one.
Therefore b = 1, substitute both a, b and c into y=ax²+bx+c as we get,
#
Answer:
Surface area of a sphere=4πr
2
=154cm
2
⇒4×
7
22
r
2
=154cm
2
⇒r
2
=
4
154
×
22
7
⇒r
2
=
4
49
⇒r=
4
49
∴r=
2
7
=3.5cm
Volume of the sphere=
3
4
πr
3
=
3
4
×
7
22
×(3.5)
3
=
21
88
×42.875=179.67cm
3
