The number of roses was 15 greater than twice the number of prunes. if the roses and prunes totaled 255, how many roses were there?

X=number of roses
y=number of prunes
we can suggest this system of equations:
x+y=255
x=2y+15

We can solve this system of equation by substitution method.
x=2y+15

(2y+15)+y=255
3y=240
y=240/3
y=80

x=2y+15
x=2(80)+15
x=160+15
x=175

there was 175 roses and 80 prunes.

For the first question the answer is a, for the second c, for the third d, for the 4th b, for the 5th a