Answer:
C. x=3 and y=−6
Step-by-step explanation:
Step: Solvex−2y=15for x:
x−2y=15
x−2y+2y=15+2y(Add 2y to both sides)
x=2y+15
Step: Substitute2y+15forxin2x+4y=−18:
2x+4y=−18
2(2y+15)+4y=−18
8y+30=−18(Simplify both sides of the equation)
8y+30+−30=−18+−30(Add -30 to both sides)
8y=−48
8y8=−488(Divide both sides by 8)
y=−6
Step: Substitute−6foryinx=2y+15:
x=2y+15
x=(2)(−6)+15
x=3(Simplify both sides of the equation)
Answer:
x=3 and y=−6
Total number of trees n = 4 + 3 + 3 = 10. Count the number of each different trees. n1=4, n2=3, n3=3. Number of ways the landscaper plant the trees in a row is = 10 ! / ( 4! * 3! * 3! ) = 3628800 / ( 24 * 6 * 6 ) = 3628800 / 864 = 4200 ways.
Therefore, the trees can be planted 4200 ways
Answer:
The answer is 20
Step-by-step explanation: