Notice that half of the coefficient of x is (1/2)(-4), or -2.
Then x^2 - 4x becomes
x^2 - 4x + 4 - 4 = 0, or (x -2)^2 = 4. Then x = -2 plus or minus 2, and the two roots are 0 and -4.
Thus, add 4 to both sides to obtain x^2 - 4x + 4 = 4.
You know that there are 25 people and each person had 36 carrots. To find how many carrots everyone has in total, you have to multiply 25 by 36.
25 times 36 is 900.
There are 900 carrots altogether.
Cos 75 = 45 + 30
Formula: cos 45 x cos 30 - sin 45 x sin 30
Cos 45 = root 2 / 2
Cos 30 = root 3 / 2
Sin 45 = root 2 / 2
Sin 30 = 1 / 2