305+213=518
1000-518= 482
The answer is there is 482 less crayons then a thousand
Answer:
I do
Step-by-step explanation:
Answer:
x + y = -2
Step-by-step explanation:
The two primary equations to remember when dealing with graphing 2-variable equations are: ax + by = c (a & b are the x & y coefficients, respectively), and the other is y = mx + c (m = slope, x & y represent themselves). There is another equation to find the slope. If not already known, it's: ∆y/∆x {∆(aka Delta) = difference}. So, since that's all been established, we can proceed to calculate your question:
1) Find your slope: 1 - (-4) = 5 for your y-variable. And -3 - 2 = -5 for your x-variable. So your slope = 5/-5 = -1
2) Use the y = mx + c equation together with either set of (x,y) coordinates to get the equation 1 = (-1)(-3) + c. Which gives you c = -2
3) So, going back to the main equation to remember, the ax + by = c, use a one of your given sets of x,y coordinates and input your known values for x, y, & c to get: a(-3) + b(1) = (-2) and do the same with other set (these are just double-checks, coefficients are all equal to 1 anyways). So, you should arrive to the equation: x + y = -2
"31-inch piece of steel is cut into three pieces"
Call the pieces a,b,c
a + b + c = 31
"second piece is twice as long as the first piece"
b = 2a
"third piece is one inch more than seven times the length of the first piece"
c = 1 + 7a
Ok, we have our equations, let's substitute the second and third into the first.
a + 2a + 1 + 7a = 31
10a + 1 = 31
10a = 30
a = 30/10 = 3
b = 2a = 6
c = 1 + 7a = 22
Check: 3 + 6 + 22 = 31, good
Answer: 3 inches, 6 inches, 22 inches