Answer:
Step-by-step explanation:Worked out on paper shown below
Also I recommended a online app called (it has wierd name but it’s helpful for algebra) mathpapa
Also I do math in pen so the last answer is messed up it’s 4c^2d and then the rest of the parentheses.Sorry for that.
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...
X=the number we have to find.
This expression "2(x+9)" is when the sum of a number and nine is doubled.
If the result is seven less than the number, we will have: x-7
We can suggest the following equation:
2(x+9)=(x-7)
2x+18=x-7
2x-x=-7-18
x=-25
answer: the number would be: -25.
Answer: 24165, I think
Step-by-step explanation:
I just multiply the kids that were there by the words they were each given
By definition of supplementary angles,
∠ABD + ∠BDE = 180
5x + 17x - 18 = 180
22x = 198
x = 9
∠ABD = 5(9) = 45°
∠BDE = 180 - 45 = 135°
