Answer:
Speed = 24 km/h
Step-by-step explanation:
Speed = Distance / Time
A cyclist travels 12 km from home to the park.
She leaves home at 13:00 and arrives at the park at 13:30.
Distance = 12 km
Time = 0.5 Hours
Speed = 12 / 0.5
Speed = 24 km/h
X − 4y = 7
5x + 9y = 6
5x − 20y = 35 //1st * 5
5x + 9y = 6
5x +9y - 5x + 20y = 6 - 35 //2nd - 1st
5x + 9y = 6
29y=-29
5x=6-9y
y=-1 //1st : 29
5x=6-9*(-1)
y=-1
x=15:5 //2nd : 5
y=-1
x=3
check:
for x=3 and y=-1 there is:
x − 4y = 7 is 3 − 4*(-1) = 7 is 7=7 ok
5x + 9y = 6 is 15-9=6 is 6=6 ok
answer: (3;-1) represents the solution.
69:
I know for a fact it can't be (B).
The answer is (A).
Reason: 6 times 9 is 54.
70:
13 is change to 15
13 plus 2 is 15
17 plus 2 is 19
I am 100% sure for question 69, but for question 70 im 100% unsure.
Answer:
80%
Step-by-step explanation:
Percent means out of 100
We need a denominator out of 100
16/20 *5/5 = 80/100
The percent is 80%
You are factoring one or more linear expressions (but are not factoring variables).
2.4n+9.6 can be divided by 2.4 and then the result mult. by 2.4:
2.4n+9.6 = 2.4 [ n + 4 ]
Also: -6z+12= 6 [ -z + 2 ] Here I have simplified linear functions but factoring out common constant coefficients (not variables).
