SAT Mc Graw Hill 2011

308 MCGRAW-HILL’S SAT

8.B This is “letter-heavy,” so you can guess and

check a solution, like (2, 11, 4), and evaluate

the expression:. Or you

can also just add 6zto both sides of the equation

to get 7x + 2 y = 12 + 6 z, then substitute:

2

72

2

12 6

2

62

1

6

+

+

=

+

()+

=

+

()+

=

z

xy

z

z

z

z

24

72 211

6

36

1

6

+()

()+ ()

==

9.B Multiply the equations:

Multiply by

3

2

3

35

3

2

9

70

:

a

c

=

⎛

⎝⎜

⎞

⎠⎟

=

a

b

b

c

a

2 c

4

3

2

3

3

5

1

7

⎛ 3

⎝⎜

⎞

⎠⎟

⎛

⎝⎜

⎞

⎠⎟

==

⎛

⎝⎜

⎞

⎠⎟

⎛

⎝⎜

⎞

⎠⎟

=

335