I am going to explain this using the substitution method, considering it appears to be the best in this situation.
We know (from the bottom equation) that y can equal 3x+20. Using this knowledge, we substitute the y in the top equation for 3x+20. Now, we have an equation that looks like this:
3x+20=x^2+2x
Now we need to move x to one side and then do some radicals (square roots).
Subtract the 2x on the right (since it is smaller, negatives = NONONO), which will give you
x+20=x^2
Now, we take the square root of both sides to get
rad(x+20)=x
Now we have to simplify. 20 doesn't have a square root, but 4 goes into 20, and 4 has a square root of 2. This now becomes
2rad(x+5)
This doesn't simplify any further... we have a problem... no way to isolate x as far as my knowledge goes... Sorry, can't help you any further than that, but another person or your teacher might be able to. R.I.P...
Answer:56
Step-by-step explanation: math
we have given that 
.
we need to express this interms of power of x .
we know that 
.
in place of n we have 2 .so 
.
so this will be the expression interms of power of x .
I think is D
5^-2*25^-1
5^-2*5^-2
5^-4
1/5^4
1/625
0,0016, 5^-4
5(r - 10) = -51
= 5r - 50 = -51
= 5r = -51 + 50
= 5r = -1
= r = -1/5
r = -0.2
