The two problems are almost identical: you have to set up a system, and then solve it.
In the first case, let
and
be, respectively, the number of girls and boys.
We know that
(the number of girls in the Spanish Club is four more than twice the number of boys). Also, we know that
(there are 61 students in total).
So, we have the system

We can use the first equation to substitute in the second

And then solve for
:

For the second problem, let
and
be the number of pins knocked down by, respectively, Carrie and John. Just like before, we have the system
And you can solve it in the very same way we solved the previous one.
Answer:
12.36
Step-by-step explanation:
price x sales tax rate =sales tax
9.80 x .06=sales tax
.59=sales tax
price + sales tax=price with sales tax included
9.80+.59=10.39
price with sales tax x tip percentage=tip amount
10.39 x .19=1.97
price with sales tax + tip = total amount
10.39+1.97=12.36
Answer: 26
Step-by-step explanation:
lets replace a and b with the numbers provided
2+4(2+4)=2+4(6)=2+24=26
The function is undefinded if the denominator, x-5, equals 0.
So

.
The domain is

.
In interval notation, this is (-infinity, 5) u (5, infinity).
This is a right angle triangle
So we can use the tangent
tan x = 5/20
tan x= 0.25
x=tan^-1 (0.25)
x= 14.04 degrees
So yes you're correct