Step-by-step explanation:
multiplying expressions.
remember every term of one expression has to be multiplied with every term of the other expression, and the results are added up (while considering their individual signs, of course).
1.
(-3×3 + 2x - 4)(3x - 2)
(-9 + 2x - 4)(3x - 2)
(-13 + 2x)(3x - 2) = -13×3x + -13×-2 + 2x×3x + 2x×-2 =
= -39x + 26 + 6x² - 4x = 6x² - 43x + 26
2.
let's do the other multiplication and compare the result with the result of 1 :
(-13 + 2x)(2x - 3) = -13×2x + -13×-3 + 2x×2x + 2x×-3 =
= -26x + 39 + 4x² - 6x = 4x² - 32x + 39
no, this product is not the same as in 1.
 
        
             
        
        
        
To multiply fractions, the numerator of the product is the product of the numerators, likewise for the denominators.
(2/3) x (4/7) x (14/5) = (2 x 4 x14) / (3 x 7 x 5)
= (112) / (105) = 1 and 1/15 .
        
                    
             
        
        
        
The number of permutations of the 4 different letters, taken two at a time, is given by:
 
 
        
        
        
Answer:
 3003 units^3.
Step-by-step explanation:
Just multiply the dimensions :
11 * 13 * 21
= 143 * 21
= 3003 units^3.
 
        
             
        
        
        
Answer:
5 and 25
Step-by-step explanation:
let the son's age be x then the father's age is x + 20
In 5 years
son = x + 5 and father = x + 20 + 5 = x + 25
Then
x + 25 = 3(x + 5) ← father is three times as old as son
x + 25 = 3x + 15 ( subtract x from both sides )
25 = 2x + 15 ( subtract 15 from both sides )
10 = 2x ( divide both sides by 2 )
5 = x and x + 20 = 5 + 20 = 25
si=on is 5 and father is 25