Answer:
500cm2
Step-by-step explanation:
2(9×20)+(7×20)
=360+140=500cm2
Step 1: convert the equation into fhe vertex form
To do you can complete squares:
y = - [x^2 + 4x + 3]
y = - [ (x + 2)^2 - 4 + 3]
y = - [ (x + 2)^2 - 1] = - (x+2)^2 + 1
Then the vertex is (-2, 1)
Now you can drasw the vertex
Step 2: Find the roots (zeros)
y = - [ (x + 2)^2 - 1] = 0
(x + 2)^2 - 1 = 0
(x+2)^2 = 1
(x+2) = (+/-) √1
x + 2 = (+/-1)
x = - 2 +/- 1
x = -1 and x = -3
Now you draw the points (-1,0) , (-3,0)
Step 3: find the interception with the y-axis.
That is y value when x = 0
y = - (0)^2 - 4(0) - 3 = -3
Then draw the point (0, -3)
Step 4: given that the coefficent of x is negative (-1) the parabola is open downward.
So, with those four points: vertex (-2,1), (-1,0), (-3,0) and (0,-3), you can sketch the function.
Answer:
7.
∠M=51°
8.∠ABC=125°
Step-by-step explanation:
when we extend one line of a triangle ,the external angle is equal to the sum of two opposite internal angles.
7.
151-2y=84+6y+3
151-2y=87+6y
151-87=6y+2y
64=8y
y=64/8=8
∠M=6y+3=6×8+3=48+3=51°
8.
20x-15=90+5x
20x-5x=90+15
15x=105
x=105/15=7
∠ABC=20x-15=20×7-15=140-15=125°
