6(21)=72 6(31)=186
add 72+186=258
258 is the answer
They would need to buy 5 dozens because the area is 56 and 12 times 5 is 60.
Step-by-step explanation:
label the numbers (x,y) and (x2,y2)
write down the distance formula
replace the xs and ys by the numbers and then solve them
Y = 2x
y = 2*(-15) = -30 . . . . . selection A is appropriate
You combine like terms.
-2x+9x
whatever answer that is you then combine the like terms -9+-1 the you just make an expression out of them.