Answer:
The value of a = 14
Step-by-step explanation:
Given
(x₁, y₁) = (2, 4)
(x₂, y₂) = (6, a)
(x₃, y₃) = (-1, 1)
A = 9 sq.units
Area of a triangle with vertices (x₁, y₁), (x₂, y₂), and (x₃, y₃) is:
substituting the values (x₁, y₁) = (2, 4), (x₂, y₂) = (6, a), (x₃, y₃) = (-1, 1), A = 9 in th formula
Multiply both sides by 2
simplify
As the area is always positive.
so
Add 18 to both sides
simplify
Divide both sides by 3
Thus, the value of a = 14
Answer:
Step-by-step explanation:the answer is 5
Answer:
p=17.43
Step-by-step explanation:
To solve this I just subtracted
p=41.13-23.7
which is
p=17.43
Let L represent length of rectangle
Let W represent width of rectangle
L=4W
2L+2W=70
Substitute 4W for L
2(4W)+2W=70
8W+2W=70
10W=70
Divide both sides by 10
W=7
Use equation from beginning
L=4(7)
L=28
Width is 7 ft, length is 28 ft
Check work
2(28)+2(7)=70
56+14=70
70=70
2 (a): <span>Lena's method is correct
</span> (b) Explanation: - We can explain that she was correct by checking the equation. In order to check that, we have to put the values of x and y.
4y = 3x + 7
Substitute for y = 10, x = 11 [ Lena's answers ]
4(10) = 3(11) + 7
40 = 33 + 7
40 = 40 [ L.H.S. = R.H.S ]
Now, checking with 2nd equation,
9x + 4y -139 = 0
9(11) + 4(10) - 139 = 0
99 + 40 - 139 = 0
139 - 139 = 0
0 = 0 [ L.H.S. = R.H.S ]
As L.H.S. is equal to R.H.S. for both equation, She was correct
3) a) System of equations would be:
x + y = 1
x - y = 11
b) Solving the equation,
Take 2nd equation,
x - y = 11
x = 11 + y
Now, substitute it in 1st equation.,
x + y = 1
11 + y + y = 1
2y = 1 - 11
y = -10 / 2
y = -5
Substitute it in 2nd equation,
x - y = 11
x - (-5) = 11
x + 5 = 11
x = 11 - 5
x = 6
In short, x is equal to 6, and y is equal to -5
Hope this helps!
