We need to solve the following system by substituition:

To solve by substituition means that we need to isolate one variable in one of the equations and replace one expression with the other. This is done below:

Then we need to replace the value of "x" in any of the two equations.

The solution is (-3,-5).
Answer: Yes.
Step-by-step explanation: 4:8 simplifies to 1:2, since he used half as many rainbow charms as he did white stars. 5:10 also simplifies to 1:2. If they both have half as many rainbow charms as white, then both of his sister’s bracelets keep the same ratio.
Answer: fail to reject the seven-minute average waiting time claim.
Step-by-step explanation:
As per given ,
Objective for test : the average waiting time is seven minutes or more.
Then ,
Since alternative hypothesis is right-tailed thus the test is an right-tailed test.
In a right tailed test , the rejection area lies on the right side of the critical value.
It means that if the observed z-value is greater than the critical value then it will fall into the rejection region other wise not.
i.e. If the value of your test statistic is less than the critical value, the correct decision is we fail to reject null hypothesis.
i.e. fail to reject the seven-minute average waiting time claim.
The complete statement would become:
If the value of your test statistic is less than the critical value, the correct decision is to fail to reject the seven-minute average waiting time claim.
Answer: b
Step-by-step explanation: b
Mj will be 60 dagree for the others use the hypatos formula