Answer:22
Step-by-step explanation:
Substitute and solve
A ratio of 5:7 means out of 12 books, 5 are in one category and 7 are in another. (The “category” isn’t specified in this problem.)
So here we’re STARTING with 36 books; we want to find a ratio that is equal to 5:7 and adds up to 36. Well 36 = 3(12), and so if we multiply each number in the ratio by 3 as well, we might get what we want. Doing that gives us 15:21, which adds up to 36 and is equal to 5:7. Boom, that’s the answer.
P.S. Here’s a question you can think about: why do ratios stay the same when you multiply each number by the same amount? (For example, why is 3:1 the same as 6:2?)
Answer:
The second one.
Step-by-step explanation:
The pattern is red with 0 arrows, blue with 1 arrow, red with 2 arrows, so it would be blue with 3 arrows.
Alright, so for AB and CD to be parallel, CX and DX would have to be equal, as is with AX and BX. In addition, for CD and AB to be parallel, all sides in both triangles are either equal or not all sides in even one triangle are equal. Therefore, CD is not 3. In addition, two sides of a triangle combined must be greater than the third, so that leaves 5, 4, and 2 for CD. If it was 5, that would mean that all sides are equal, so that leaves 4 and 2. However, I don't see anything to prove either one right, sorry:/
-20=-4x-6x
4x+6x=20
10x=20
x=20:10
x=2
proof:
-20=-4×2-6×2
-20=-8-12
(-8)+(-12)=-20
