<u>Answer</u>:
x = 7, y = 2
<u>Explanation</u>:
equations given:
x + 7y = 21
x + 4y = 15
make "x" the subject:
x + 7y = 21
x = 21 - 7y .........equation 1
x + 4y = 15
x = 15 - 4y .......equation 2
Solving both the equations simultaneously:
15 - 4y = 21 - 7y
-4y + 7y = 21 - 15
3y = 6
y = 6 ÷ 3
y = 2
If y is 2 
Then x = 21 -7y;
x = 21 - 7(2)
x = 21 - 14
x = 7
 
        
                    
             
        
        
        
Answer:
y = 4/3x - 4
Step-by-step explanation:
to find the equation of a line with 2 points, we use the slope formula which is:

we will use (6,4) as ![x_1[tex] and [tex]y_1](https://tex.z-dn.net/?f=x_1%5Btex%5D%20and%20%5Btex%5Dy_1) and we will use (-3,-8) as
 and we will use (-3,-8) as ![x_2[tex] and [tex]y_2](https://tex.z-dn.net/?f=x_2%5Btex%5D%20and%20%5Btex%5Dy_2) . we plug this into the slope formula:
. we plug this into the slope formula:

-8 - 4 = -12
-3 - 6 = -9
the slope is 
but we can simplify this further by dividing the fraction by -3
-12 / -3 = 4
-9 / -3 = 3
the simplified version of the slope is 
we can write this in slope-intercept form which is y =mx + b, with b being the y intercept and m being the slope
y = 4/3x + b <--- we need to solve for <em>b</em> in order to find the y intercept, so substitute x & y for a point on the line, we can use any point we are given, but for this example i will use (6,4)
4 = 4/3(6) + b < multiply 4/3 x 6
4 = 8 + b < subtract 8 from both sides
-4 = b
our y intercept would be (0,-4)
the equation looks like the following:
y = 4/3x - 4, which is our answer
 
        
             
        
        
        
Answer:
Pyramid
V= 240 m^3
Step-by-step explanation:
The volume of a pyramid is 1/3 the Base times the height.
1/3x(10x8)x9
 
        
             
        
        
        
Answer:
(x, y) = (-3, -6)
Step-by-step explanation:
The second equation can be used to write an expression for y:
... -5x -21 = y . . . . . . . add y-21 to both sides
This expression can be substituted for y in the first equation:
... 6 = -4x +(-5x -21)
... 27 = -9x . . . . . add 21, collect terms
... -3 = x . . . . . . . divide by -9
Using this value of x in the expression for y, we find ...
... -5(-3) -21 = y = -6
The solution is x = -3, y = -6.
 
        
             
        
        
        
The first figure has 3 angles, the second one has 4 angles, the third one has 5 angles so the next one will have 6 angles.
The violet figures inside stick with each side of the outer figures in the middle, so the last figure will look more less like in the attachment.