Multiply the first equation by -1 and add it to the second one, getting
y-4z=-10
Multiply the first equation by 2 and add it to the third one, getting -2y+10z=26
As you can see, we eliminated x and turned it into two equations with 2 variables.
Multiply the first new equation by 2 and add it to the second one to get
2z=6 and z=3. Substitute it in to -2y+10z=26 to get y=2 and substitute it into <span>-x+y+z=4 to get x=1</span>
Answer:
The dimensions of the rectangle are 22cm of length and 15cm of width
Step-by-step explanation:
To solve this we first have to know the formula to calculate the area of a rectangle
a = area = 330 cm²
L = length =
w = width = L - 7cm
a = l * w
we replace with the known values
330 cm² = L * (l - 7cm)
330 cm² = L² - 7Lcm
0 = L² - 7Lcm - 330 cm²
when we have an equation like this we can use bhaskara
a = 1
b = -7Lcm
c = -330cm²
ax² + bx + c = 0
x = -b(±)√(b² - 4ac)/2a
we replace with the known values
L = -(-7cm)(±)√(7² - 4(1)(-330cm²)) / 2(1)
L = 7cm(±)√(49 + 1320cm²)) / 2
L = 7cm(±)√(1369cm²)) / 2
L1 = (7cm + 37cm) / 2
L1 = 44cm / 2 = 22cm
L2 = (7cm - 37cm) / 2
L2 = -30cm / 2 = -15cm
The positive represents the unknown with which we work (L) and the negative with which we do not work (W)
The dimensions of the rectangle are 22cm of length and 15cm of width
1. The coefficient of x is the constant of variation. It is 40.
2. -12 = -2*6 . . . . . you know this because you know your times tables
.. f(x) = -2x
Answer:
A = 70 mm²
Step-by-step explanation:
The area (A) of a trapezoid is calculated as
A = 
h (b₁ + b₂)
where h is the perpendicular height and b₁, b₂ the parallel bases
Here h = 10, b₁ = 10, b₂ = 4 , then
A = × 10 × (10 + 4) = 5 × 14 = 70 mm²
Answer:
b ASA
Step-by-step explanation:
