There are 3 ways of solving a simultaneous problem, substitution method, elimination method and Gauss-Jordan method. I'm gonna use the substitution method since it's easier and i think it would suit your level more.
First let's try solving for y since it's easier to start with.
Firstly we have to find an equation for x:

Great, now we can use the substitution method to find the value of y using the first equation:

Now we know that y=1 we can solve the first equation we made:

And the answer is 
Double check:

And that's our final answer! (4,1)
He bikes 4/10 of a mile in 1/5 of an hour
That is 4/10 miles in 1/5 hours
Average speed = Distance/ time = 4/10 ÷ 1/5 = 4/10 × 5/1 = 2 miles/hour
3(7v-5)-v(10v-9) = 21v - 15 -10v² + 9v = - 10v² + 30v - 15
Yes, this is correct. The tenths place is the first number to the right of the decimal. There is a 3 in that spot
To find if it rounds up or down, follow this rule.
Less than 5 round down and greater than 5 round up.
For this you look to the number next to it which is 7.
It rounds up so it is 9.4
Answer:
Alternate Interior Angles:
∠3 ≅ ∠5
Corresponding Angles:
∠3 ≅ ∠7
∠4 ≅ ∠8
Supplementary Angles:
∠3 is supplementary to ∠6
Step-by-step explanation: