Sat 数学历年真题

Test 1 Section 3

Algebra to start with.

Let’s write our given: x = 4

What are we looking for? The answer that has the greatest value.

There are two ways to do this, the first being: Work every possible answer by inputting 4 for x:

(4+1)(4+2) = (5)*(6)=30 (answer)

(4+1)(4-1) = (5)*(3)=15 (4-2)(4+2) = (2)*(6)=12

(4-2)(4+1) = (2)*(5)=10 (4-4)(4+4) = (0)*(8)=0

Or logic it out:

x. If x were really large,

this might not matter, but x is 4, so taking 2 away from it reduces it by 50%. (C) and (D) are gone.

they differ. Is there any way (x+2) can be smaller than (x1)? No way. (B) is gone.

Test 1 Section 3 Question 2 Variable Problem

What are we looking for? What speed C is traveling when B’s speed is 7 mph (so B=7 is a given).

The table reflects the speeds we will find.