1. Eyeballing the data, the best fit will be pretty close to a line between the leftmost point and the rightmost point.
We estimate those points as (4,220) and (28,470)
The point point form for a line joining (a,b) and (c,d) is
(c-a)(y-b) = (d-b)(x-a)
(28 - 4)(y - 220) = (470 - 220)(x - 4)
24(y - 220) = 250(x-4)
24y - 5280 = 250x - 1000
24y = 250 x + 4280
y = (250/24) x+ (4280/24)
Approximately that's,
y = 10.4 x + 178
Answer: 4th choice, 10.4x + 180
2. For 48 wheelbarrows,
y = 10.4(48)+180 = 679.2
Answer: 679.2 liters of sand
For complex number, the magnitude is pretty straight forward:
sqrt(6^2 + 2^2) = sqrt(40)
For any a + bi, the magnitude will be sqrt(a^2 + b^2)
Answer:
3(Y-2) +5Y =Y+22
3Y-6 +5Y=Y+22
3Y -6 +5Y-Y-22=0
3Y+5Y-Y-6-22=0
7Y-28=0
7Y=28
Y=28/7
Y=4
Step-by-step explanation: