Answer:
Given the system of equation:
......[1]
......[2]
we can rewrite equation [2] as;
......[3]
Substitute equation [3] into [1] to eliminate x, and solve for y;

Using distributive property: 

Combine like terms;
16 - 8y = -4
Add 4 to both sides we have;
20 - 8y = 0
Add 8y to both sides we have;
20 = 8y
Divide 8 to both sides we have;

Substitute the y-value in [3] we have;

x = 8 - 5 = 3
Therefore, the expression should be substituted into the first equation is,
and also the value of x = 3 and y = 2.5
Answer:
The slope equation of the line AB is 
Step-by-step explanation:
Here, the given points are A (2, 3) and B (7,4).
Now, slope of any line is given as :

or, 
Hence, the slope of the line AB is (1/5)
Now , A POINT SLOPE FORM of an equation is
(y - y0) = m (x - x0) ; (x0, y0) is any arbitrary point on line.
Hence, the equation of line AB with slope (1/5 ) and point (7,4) is given as:

or, 5y - 20 = x -7
⇒ x - 57 + 13 = 0 ( SIMPLIFIED FORM of equation)
Hence, the slope equation of the line AB is 
Answer:
The new point is (-3,-1)
Step-by-step explanation:
yessir
Answer:
the cost of 3 apples and 7 oranges be £15 and £35 respectively
Step-by-step explanation:
Let us assume the apple be x
And, the oranges be y
Now according to the question
5x + 4y = £45
And,
2x + 8y = £50
Multiply by 2 in equation 1
So,
10x + 8y = £90
2x + 8y = £50
8x = £40
x = £5
And, y be
5(£5) + 4y = £45
£25 + 4y = £45
4y = 20
y = £5
So, the cost of 3 apples and 7 oranges be £15 and £35 respectively