18 dollars. div ide 90 by 80 to get 72. and subtract 90 from 72
X²+15x+36<0
at first solve quadratic equation
D=b²-4ac= 225-4*1*36= 81
x=(-b+/-√D)/2a
x=(-15+/-√81)/2= (-15+/-9)/2
x1=(-15-9)/2=-12
x2=(-15+9)/2=-3
we can write x²+15x+36<0 as (x+12)(x+3)<0
(x+12)(x+3)<0 can be 2 cases, because for product to be negative one factor should be negative , and second factor should be positive
1 case) x+12<0, and x+3>0,
x<-12, and x>-3
(-∞, -12) and(-3,∞) gives empty set
or second case) x+12>0 and x+3<0
x>-12 and x<-3
(-12,∞) and (-∞,-3) they are crossing , so (-12, -3) is a solution of this inequality
This is what I got. I don’t know if it’s 100% right but I think it is.
X = 3
y = -3
You will see this using any graphing tool at your disposal.
<em>429 cm²</em>
- Step-by-step explanation:
<em>A(blue) =</em>
<em>= 2×6cm×10cm + 2×6cm×8cm + 8cm×10cm + (8cm×10cm - 5cm×4cm)</em>
<em>= 120cm² + 96cm² + 80cm² + 60cm²</em>
<em>= 356 cm²</em>
<em>A(green) =</em>
<em>= 4cm×5cm + 2×5cm×5cm/2 + 4cm×7cm</em>
<em>= 20cm² + 25cm² + 28cm²</em>
<em>= 73 cm²</em>
<em>A(total) =</em>
<em>= A(blue) + A(green)</em>
<em>= 356 cm² + 73 cm²</em>
<em>= 429 cm²</em>
