21 x 10⁴

2.1 x 10⁵

2.1 x 10⁷

21 x 10⁶

$7.84\times10^4$

$7.84\times10^{-4}$

$0.784\times10^{-3}$

$78.4\times10^{-3}$

 $20.14\times10^7$  

 $20.14\times10^2$  

 $2.014\times10^7$  

 $2.014\times10^2$  

 $82\times10^0$  

 $8.2\times10^0$  

 $82\times10^3$  

 $8.2\times10^6$  

4x - 6 = 20

6x + 3 < 18

3x + 7 > 10

$3y+2\ne4$

$5x+7=2$

$6y+7x=16$

$x^2-1=4$

$m=2+3n$

$17\times4=68$

$45+0=45\times0$

$14-14=24\times0$

$45+\left(-15\right)=-15+\ 45$

$4a-10=8\ \ \ \ \ \ \ \ [7]$

$2\left(k+6\right)=-6\ \ \ \ \ \ \ \ \left[-9\right]$

$\frac{t}{5}=10\ \ \ \ \ \ \ \ \left[5\right]$

$\frac{-4}{7}k=\frac{7}{4}\ \ \ \ \ \ \ \left[-1\right]$

$7-y=15$

$y-7=15$

$y+7=15$

$7y=15$

$3a-3=20$

$3a+3=20$

$3+5a=20$

$3-5a=20$

7(x + 1) - 6 = 22

2(x + 2) + 8 = 22

4(x + 2) + 5 = 21

4(x + 2) + 5 = 23

7(x + 1) - 6 = 22

7(x + 1) - 6 = 24

4(x + 2) + 5 = 21

2(x + 2) + 8 = 22

3

4

จำนวนทุกจำนวน

ไม่มีจำนวนใดเป็นคำตอบ

-42

-43

-44

-45

2

2.5

3.

3.5

3

-3

4

-4

1

0

-1

2

1.2

-1.2

0.833

-0.833

2

-2

1

-1