A)
The question tells us that
y + z = 180
And
y=3x+20
z=x
So we put them in the first formula:
y + z = 180
(3x + 20) + x = 180
Add and get x to one side:
4x + 20 = 180
4x + 20 - 20 = 180-20
4x = 160
Divide both sides by 4
x = 40
B)
Put x back in to equation to get size of each angle:
Y =3x +20
Y=3(40)+20
Y=120+20
Y=140
Z=x
Z=40
Verify: y+z=180
140+40=180
180=180
Are you sure you want ONLY the coefficient of b? If you expand this, you will have b in 3 of 4 terms.
According to Pascal's Triangle, the coefficients of (a+b)^4 are as follows:
1
1 2 1
1 3 3 1
1 4 6 4 1
So (a+b)^4 would be 1a^4 + 4a^3b + 6a^2b^2 + 4ab^3 + b^4
Here, you want (3 + b)^4. Here's what that looks like:
3^4 + 4[3^3*b] + 6[3^2*b^2] + 4[3*b^3] + 1[b^4]
Which coeff did you want?
Exact Form:
35/12
Decimal Form:
2.916
Mixed Number Form:
2 11/12
The inverse of subtraction is addition
X's cancel 5y = 20 y= 4 X=0