310-85=225
225/25=9
Therefore it will take her 9 weeks
Answer: Yes
Step-by-step explanation:
2x+8y=6
-8y -8y
2x = -2y
Divide by two so x will be by itself, so the answer will be -1y.
5x+20y=2
-20y -20y
5x = -18y
Divide by 5 so x will be by itself, so the answer will be -3y.
Step-by-step explanation:
given :
2x - 3y = 11
-6x + 8y = 34
find : the solutions of the system by using Cramers Rule.
solutions:
in the matrix 2x2 form =>
[ 2 -3] [x] [11]
=
[-6 8] [ y] [34]
D =
| 2 -3 |
|-6 8 |
= 8×2 - (-3) (-6)
= 16-18 = -2
Dx = | 11 -3 |
| 34 8 |
= 11×8 - (-3) (34)
= 88 + 102
= 190
Dy = | 2 11 |
|-6 34 |
= 2×34 - (-6) (11)
= 68 + 66
= 134
x = Dx/D = 190/-2 = -95
y = Dy/D = 134/-2 = -67
the solutions = {-95, -67}
Answer:
6
Step-by-step explanation:
it would be six in one hour he would clean 2 houses in two 4 houses then in three it would be six