Question

10. 9 - (8x - 11) = 12 11. (6x+1)-(3 -2x) = 14 12. 2x - (6x - 5) = 45 13. 5x - (7x + 7) = 9 14. 2x - (6x + 1) = 9 15. 4x - (7x - 2) = 17 16. 2x+7=3x - 2(3x - 1) 17. 4 - 2(x+3)=4(x - 5) 18. 5x+3 =7x - 5(2x+1) 19. Зу - (5 - у) = 11 20, 3x-2 ＿ 2+x 21.9

Answer 1

Ответ:

10) 8x-11=9-12

8x-11=-3

8x=-3+11

8x=8

x=8÷8

x=1

9-(8×1-11)=12

9-(-3)=12

9+3=12

12=12

11) 6x+1-3+2x=14

8x=14-1+3

8x=16

x=16÷8

x=2

(6×2+1)-(3-2×2)=14

13-(-1)=14

13+1=14

14=14

12) 2x-6x+5=45

-4x=45-5

-4x=40

x=40÷(-4)

x=-10

2×(-10)-(6×(-10)-5))=45

-20-(-65)=45

-20+65=45

45=45

13) 5x-7x-7=9

-2x=9+7

-2x=16

x=16÷(-2)

x=-8

5×(-8)-(7×(-8)+7)=9

-40-(-49)=9

-40+49=9

9=9

14) 2x-6x-1=9

-4x=9+1

-4x=10

x=10=(-4)

x=x=-2,5

2×(-2,5)-(6×(-2,5)+1)=9

-5-(-15+1)=9

-5-(-14)=9

-5+14=9

9=9

15) 4x-7x+2=17

-3x=17-2

-3x=15

x=15÷(-3)

x=-5

4(-5)-(7×(-5)-2)=17

-20-(-35-2)=17

-20+37=17

17=17

16) 2x+7==3x-6x+2

2x-3x+6x=2-7

5x=-5

x=-5÷5

x=-1

2×(-1)+7=3×(-1)-6×(-1)+2

5=-3+6+2

5=5

17) 4-2(x+3)=4(x-5)

4-2x-6=4x-20

-2x-4x=-20-4+6

-6x=-18

x=-18÷(-6)

x=3

4-2(3+3)=4(3-5)

4-2×6=4×(-2)

4-12=-8

-8=-8

18) 5x+3=7x-5(2x+1)

5x+3=7x-10x-5

5x-7x+10x=-3-5

8x=-8

x=-8÷8

x=-1

5×(-1)+3=7×(-1)-5(2×(-1)+1)

-2=-7+5

-2=-2

19) 3y-(5-y)=11

3y-5+y=11

4y=11+5

4y=16

y=16÷4

y=4

3×4-(5-4)=11

12-1=11

11=11