3x + 5y = 1 . . . . . . . . (1)
7x + 4y = -13 . . . . . . .(2)
(1) x 7: 21x + 35y = 7 . . (3)
(2) x 3: 21x + 12y = -39 .(4)
(3) - (4) = 23y = 46
y = 46/23 = 2
60 divided by 5,
is 12.
In which case,
12 times 3...
Is 36$.
So Leo would pay 36$ for 3 DVDs at the rate of 12$ for each DVD
Opposite angle of a quadrilateral add up to 180 degrees.
This means Angle A plus Angle C equal 180.
We can solve for X using that, then solve for Angle B.
2x-7 + x +4 = 180
Simplify:
3x -3 = 180
Add 3 to each side:
3x = 183
Divide both sides by 3:
x = 183 /3
x = 61
Now we know x, replace x with 61 in the equation for Angle B:
Angle B = 2x+3 = 2(61) +3 = 122 +3 = 125 degrees.
