7b Mathematics supplementary exercise answer 9.5 Factorization (1)

C B 8a2 (refers to the square of 8a)

4.8m2n-2mn = 2mn * 4m-2mn * 1 = 2mn *(4m-n)

12 XYZ-9x2y 2 = 3xy * 4y-3xy * 3xy = 3xy *(4x-3xy)

6a 2-9ab+3a = 3a * 2a-3a * 3b+3a * 1

-2 x2- 12xy 2+8xy 3 =-2x * x-2x * 6 y2+(-2x)*(-y3)=-2x *(x-6 y2-y3)

5. It is known that a+b=6 and ab=7. Find the value of a2b+ab2.

a2b+ab2=ab*a+ab*b=ab*(a+b)

When a+b=6 and ab=7, the original formula =7*6=42.

6. (1)17 * 3.14+61* 3.14+22 * 3.14 (2)1.

= 3. 14 * ( 17+6 1 +22) = 2 *( 10*2)+2 *( 14*2)+2 *32.

=3. 14* 100 =4*(40+28+32)

=3 14 =4* 100=400

7. The formula = 65438 square +00 * 6.03+65438 square +00 * 8.48+65438 square +00 *5.49 is omitted.

= 10 squared *(6.03+8.48+5.49)

= 100*20=2000

It's done. . . . I want to tell you. . . Use it after factorization, be studious and clear-headed! !

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