Answer:
x=−3 or x=5
Step-by-step explanation:
x2−2x−15=0
Step 1: Factor left side of equation.
(x+3)(x−5)=0
Step 2: Set factors equal to 0.
x+3=0 or x−5=0
x=−3 or x=5
Answer: $13.25 each ticket
Step-by-step explanation: 530 divided by 40
86.88 kilometers is 53.98 miles
Let m and j be the current ages of Matthew and Jenny, respectively.
Now, Matthew is 3 times as old as Jenny, so the variables are in the following relation:

In 7 years, both of them will be 7 years older, i.e. their ages will be m+7 and j+7, and Matthew will be twice as old:

Now, remembering that m=3j, we can rewrite the second equation as

So, Jenny is 7 and Matthew is 21 (he's 3 times older).
In fact, in 7 years, they will be 14 and 28, and Matthew will be twice as old.
add 4n and 5n, which is 9. 9n=-9, and if u divide both sides by nine, n=-1