Answer:
Step-by-step explanation:
for nr. 1
sum of angles in a triangle=180
x=180-(81+84)=15
acute triangle
for nr.2
x=180-(24+36)=120
obtuse triangle
Answer:
2<x<3
Step-by-step explanation:
4x-4<8 AND 9x+5>23
Solve the first inequality
4x-4<8
Add 4 to each side
4x-4+4 <8+4
4x<12
Divide by 4
4x/4 <12/4
x <3
Solve the second inequality
9x+5>23
Subtract 5 from each side
9x+5-5>23-5
9x >18
Divide by 9
9x/9>18/9
x>2
Put together
x<3 and x>2
2<x<3
Answer:
Step-by-step explanation:
The answer A on 2021
Answer:
y = -2x^2 - 4x - 1
Step-by-step explanation:
We can see that the graph passes through (-2, -1), (-1, 1) and (0, -1).
Let's solve
ax^2 + bx + c = y
a(-2)^2 + b(-2) + c = -1
4a - 2b + c = -1
a(-1)^2 + b(-1) + c = 1
a - b + c = 1
a0^2 + b0 + c = -1
c = -1
we got c = -1 so we input it into the other 2
4a - 2b - 1 = -1
4a - 2b = 0
2a - b = 0
2a = b
a - b - 1 = 1
a - b = 2
a = b + 2
Let's input b = 2a
a = 2a + 2
-a = 2
a = -2
b = 2a = 2*(-2) = -4
c = -1
y = -2x^2 - 4x - 1
