390.20 is the answer because 4%of 2880 is 115.20 plus 275.00 is 390.20
2. WXZ=YXZ
3. Reflexive property of equality
(if they are angles)-
4. WXZ=YXZ ~~Reason- Congruent angles have equal number of degrees
(if they are triangles-more likely judging by the problem)-
4. Triangle WXZ=YXZ ~ Reason- SAS Congruence Postulate
The line passing through (3, -1) and (-1, 5) has this slope:
5+1
m = ---------- = -3/2
-1-3
We need to find the y-intercept. To do this, substitute the knowns (-3/2 for m, -1 for y and 3 for x) into the slope-intercept equation:
-1 = (-3/2)(3) + b. Then: -1 = -9/2 + b, and so b = 9/2 - 1 = 7/2.
The desired equation is y = (-3/2)x + 7/2.
So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.
