She worked as a carpenter for 12 hours and as a blacksmith for 18 hours.
Assuming you mean she earned $20 as a carpenter and $25 as a blacksmith per hour, with a total of 30 hours for $690,
let c represent carpenter hours and b for blacksmith hours.
20c + 25b = 690
c + b = 30
Subtract b from each side so that c = 30 - b
Plug this value into the first equation
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
600 + 5b = 690
5b = 90
b = 18
To find c, plug this value of b into the other equation
c + 18 = 30
c = 12
The sum of the magnitudes will be the magnitude of the sum when the vectors have the same direction.
Add $9.40 two times what ever you get multiply that 15 and there’s your answer
Answer:
Step-by-step explanation:
Lets x = width
height = 2x - 4
A = 1/2 b h
63 = 1/2 (x)(2x-4)
126 = 2x^2 - 4x
2(x^2 - 2x - 63) = 0
2(x - 9)(x + 7) = 0
x - 9 = 0; x = 9
x + 7 = 0; x = -7
so width = 9
height = 2(9) - 4 = 18 - 4 = 14
answer
width = 9 in
height = 14 in
