Write a system of equations and solve.
x + y = 10
5x + 10y = 90
Multiply and combine equations
-5x - 5y = -50
5x + 10y = 90
------------------
5y = 40
y = 8
x = 2
There are 2 nickels and 8 dimes in the jar. Hope this helps! :)
4-4=0 is an example of that
Multiply the first equation with (-1)
you should get this
-6r + 3t = -6
6r + 8t = -16
start to eliminate
11t = -22
divide by 11
t = -2
substitute
6r - 3(-2) = 6
6r + 6 = 6
6r = 6 - 6
6r = 0
r=0
First, take off 4 feet of Stacy's rope, which is 19. (23-4=19). Then, divide 19 by 3. It should equal 6.3...
-(-4) = 4, so the opposite, if I understand what they mean, would be -4.