Answer:
9
Step-by-step explanation:
7r+18=r²
r²-7r-18=0
factorizing
r²+2r-9r-18=0
r(r+2)-9(r+2=0
(r-9)(r+2)=0
r-9=0
r=9
check
(r²)=(9*9)=81
7r+18=7(9) + 8=81
Answer:
Step-by-step explanation:
Answer:
44 cubic meters
Step-by-step explanation
9 + 4 + 6 = 19
9/19 of the patio will be cement
4/19 of the patio will be gravel
6/19 of the patio will be stones
Work out the amount of gravel - 4/19 * 209 = 44 cubic meters
:)
Answer:
50%
Step-by-step explanation:
50 to 75 is a change of 50% (25 is the difference between the two numbers, and 25 is 50% of 50).