Part n 13)
we have that
3x+y=-2----> multiply by both sides----> 6x+2y=-4----> equation 1
x-2y=4---> equation 2
add equation 1 and equation 2
6x+2y=-4
x-2y=4
--------------
7x=0----------> x=0
x-2y=4-----> 0-2y=4-----> y=-4/2----> y=-2
the solution is the point (0,-2)
the answer part n 13) is the option B
there is exactly one solution (0,-2)
Part 14)
let
x----> the number of years
y-----> height of the tree in ft
case a) y=8+x-----> equation 1
case b) y=10+(1/2)x----> equation 2
equate equation 1 and equation 2
8+x=10+(1/2)x----> multiply by 2 both sides----> 16+2x=20+x
2x-x=20-16
x=4 years
for x=4 years
case a) y=8+x---> 8+4----> y=12 ft
case b) y=10+(1/2)*4----> 10+2---> y=12 ft
the answer part 14) is
4 years
Part 15)
let
x----> number of adult tickets
y----> number of child tickets
we know that
x+y=14-----> x=14-y-----> equation 1
9x+5y=110-----> equation 2
substitute equation 1 in equation 2
9*[14-y]+5y=110----> 126-9y+5y=110
9y-5y=126-110
4y=16
y=4
x+y=14----> x=14-y-----> x=14-4----> x=10
so
number of adult tickets is 10
number of child tickets is 4
the answer Part 15)
number of adult tickets is 10
