tailieunhanh - Sat - MC Grawhill part 34

Tham khảo tài liệu 'sat - mc grawhill part 34', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 320 McGRAW-HILL S SAT Answer Key 5 Factoring Concept Review 5 1. To write it as a product result of multiplication . 2. x2 - b2 x b x - b x2 2xb b2 x b x b x2 - 2xb b2 x - b x - b x2 a b x ab x a x b 3. If the product of a set of numbers is 0 then at least one of the numbers must be 0. 4. 108 2 2 3 3 3 5. 21mn 3 7 m n and 75n2 3 5 5 n n so the least common multiple is 3 5 5 7 m n n 525mn2. 6. 108x6 2 2 3 3 3 x x x x x x and 90x4 2 3 3 5 x x x x so the greatest common factor is 2 3 x x x x 6x4. 7. 1 - 49x4 1 - 7x2 1 7x2 8. m2 7m 12 m 4 m 3 9. 16x2 - 40x 25 4x - 5 4x - 5 4x - 5 2 10. y 43 y-43 y2-y43 y43-43 y2-3 11. f x 1Ì f x f x if x f x V1 12 3 J 15 2 12 A 5J f2jf2 J 1 ifx f 1Y f 3 Jf 5J f 3Ẳ 2 J x2 x x 1 10 4 15 6 x2 19x . 1 10 60 6 12. 3x- W5ị 3x 3x - 3x 5 - 3x 5 245 243 9x2 -12xV5 20 13. Subtract 12x Factor 4x2 12x 4x2 - 12x 0 4x x - 3 0 Use zero product property x 0 or 3 14. x2 - 8x 33 Subtract 33 x2 - 8x - 33 0 Factor x - 11 x 3 0 Use zero product property x 11 or -3 15. Factor Substitute z 5 Divide by 15 3xz - 3yz 60 3z x - y 60 15 x - y 60 x - y 4 SAT Practice 5 1. C 72 2 2 2 3 3 and 54 2 3 3 3 so the least common multiple is 2 2 2 3 3 3 216. 216 minutes is 3 hours 36 minutes. 2. E You can solve this one simply by plugging in x 7 and y 1 and evaluating 7 - 1 2 - 7 1 2 36 -64 -28. Or you could do the algebra x - y 2 - x y 2 FOIL x2 - 2xy y2 - x2 2xy y2 Simplify Substitute xy 7 3. 5 FOIL Subtract x2 and a Factor Divide by x Subtract 1 -4xy -4 7 -28 x a x 1 x2 6x a x2 x ax a x2 6x a x ax 6x x 1 a 6x 1 a 6 a 5 4. A The slope is the rise over the run which is the difference of the y s divided by the difference of the x s m2 - n2 m n m - n m - n m n m - n Or you can just choose values for m and n like 2 and 1 and evaluate the slope numerically. The slope between 1 1 and 2 4 is 3 and the expression in A is the only one that gives a value of 3. 5. A a b 2 a b a b a2 2ab b2 Commute a2 b2 2ab Substitute ab -2 and a2 b2 8 8 2 -2 4 6. D Factor f2 - g2 f g f- g .