A two digit number has a tens digit and a ones digit.
Let's say x = tens digit and y = ones digit 
"The sum of the digits is 5"
x + y = 5 
The next phrase is "the number multiplied by 3 is 42" but we need to represent the number using the digits. So they need to be multiplied first by their place value and added together. [Example: 34 = 3(10) + 4(1)]
The number is: 10x + y 
3(10x + y) = 42 
The system of equations: (two equations for two unknowns) 
x + y = 5 
30x + 3y = 42 
Then you can use substitution or elimination to combine and solve. 
I'll use elimination, multiply the entire top equation by -3 and add the equations together. y will cancel out
-3x - 3y = -15 
30x + 3y = 42 
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27x + 0 = 27 
x = 1 
then plug x = 1 into either equation to find y
1 + y = 5 
y = 4 
remember the x and y represent digits so the number xy is 14 
        
             
        
        
        
La solution:
625 cm^2.
Explication étape par étape:
Si la forme est rectangulaire, elle aura la plus grande superficie possible quand la longueur équivaut à la largeur. Pour avoir un périmètre de 100 cm, cela signifie que chaque côté doit faire 25 cm. 
La superficie serait alors de 25 cm x 25 cm = 625 cm^2.
 
        
             
        
        
        
1/2 I’m just doing this answer because I need to finish setting up the account so it’s wrong my bad
        
                    
             
        
        
        
Answer:  The two roots are x = 3/2 and x = -2
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Explanation:
You have the right idea so far. But the two numbers should be 3 and -4 since 
The -1 being the coefficient of the x term. 
This means you need to change the -3x and 4x to 3x and -4x respectively. The other inner boxes are correct.
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Refer to the diagram below to see one way to fill out the box method, and that helps determine the factorization. 
If we place a 2x to the left of -2x^2, then we need an -x up top because 2x*(-x) = -2x^2
Then based on that outer 2x, we need a -2 up top over the -4x. That way we get 2x*(-2) = -4x
So we have the factor -x-2 along the top
The last thing missing is the -3 to the left of 3x. Note how -3*(-x) = 3x in the left corner and -3*(-2) = 6 in the lower right corner.
We have the factor 2x-3 along the left side. 
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The two factors are (2x-3) and (-x-2) which leads to the factorization (x+3)(-x+2)
The last thing to do is set each factor equal to 0 and solve for x
- 2x-3 = 0 solves to x = 3/2 = 1.5
- -x-2 = 0 solves to x = -2
The two roots are x = 3/2 and x = -2
 
        
             
        
        
        
h=9
A=((a+b)/2)h
234=((32+20)/2)h
234=(52/2)h
234=26h
9=h