Replace each "x" in the original equation with (4):
3(4)^2 + 2(4) - 5
= 3(16) + 8 - 5 = 48 + 8 - 5. Can you finish this?
Step-by-step explanation:
there are 2 similar triangles : ABE and DCE
that means they have the same angles, and the scaling factor from one triangle to the other is the same for every side.
and that means that
DE/AE = EC/BE (= DC/AB)
we know that
AE = AD + DE
BE = BC + EC
a.
so, we have actually
DE/(AD+DE) = EC/(BC+EC)
DE/(10+DE) = 8/(2+8) = 8/10 = 4/5
DE = 4(10+DE)/5
5DE = 4(10+DE) = 40 + 4DE
DE = 40 cm
b.
AD/DE = 3/5
BC/EC must be 3/5 too.
15/EC = 3/5
15 = 3EC/5
75 = 3EC
EC = 25 cm
Rewriting the question, the given lengths that were cut from the board were 30 3/4 inches, 12 1/4 inches, and 16 1/4 inches. To obtain the remaining length of the board, all of the measurements cut are to be added and subtracted from 72 inches. This is shown below:
30 3/4 + 12 1/4 + 16 1/4 = 237/4 = 59.25 inches.
Remaining length of board = 72 - 59.25 = 12.75 inches.
Therefore, there will be 12.75 inches remaining of the board.
a and c are the anwsers to this it if you look at the back of the book it will give you anwsers
