Solve the system: 5x+6y=−20 9y+2x=25
1 answer:
Answer:
(x, y) = (-10, 5)
Step-by-step explanation:
This one can be a little tricky because the variables in the equations are not in the same order. It might help to rewrite the system as ...
- 5x +6y = -20
- 2x +9y = 25
Multiplying the first equation by 3 and subtracting 2 times the second equation can eliminate the y-variable:
3(5x +6y) -2(2x +9y) = 3(-20) -2(25)
11x = -110 . . . . . . simplify
x = -10 . . . . . . . . divide by 11
5(-10) +6y = -20 . . . substitute for x in the first equation
6y = 30 . . . . . . . . add 50
y = 5 . . . . . . . . . . divide by 6
The solution is (x, y) = (-10, 5).
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Answer:
Length of rectangular strip = 12
area of rectangular strip = 2*12 = 24
Area of square = x^2 = 12^2 = 144
Step-by-step explanation:
Area of square x^2
area of rectangle is given by length * width
Length of rectangular strip = x
width of rectangular strip = 2
area of rectangular strip = length * width = 2*x = 2x
Area of square piece of paper when rectangular strip is taken away from it
= Area of square - area of rectangular strip
=
It is given that Area of square piece of paper when rectangular strip is taken away from it is 120 square units.
Thus,
Thus,
either x+10 = 0 or x -12= 0
x = -10 or x = 12
but length cannot be negative hence neglecting x = -10
hence value of x is 12.
Hence,
Length of rectangular strip = 12
area of rectangular strip = 2*12 = 24
Area of square = x^2 = 12^2 = 144