21.Factorize : x² +10x+21
22.Factorize: x² -2x-35
23.Solve : 2x+28 = 9x-56​

Step-by-step explanation:

21.

22.

23.

hope it helps

21. (x+7)(x+3)

22. (x-7)(x+3)

23. 12

Step-by-step explanation:

X^2+10x+21

(X+7)(x+3)

(We know that 7*3 is equal to 21 and that 7+3= 10)

Now try the same thing for 22.

(X-7)(X+5)

(-7*5= -35 . and -7+5=-2)

23. Use SPOE to get like terms to one side:

-7x=-84

Then use DPOE to find the value of X

x=12

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²