Answer:
3
Step-by-step explanation:
all same signs means positive
3x^2 + 4x - 5 = 0
x = [-b ±√(b^2 - 4ac)]/2a
a = 3
b = 4
c = -5
x = [-4 ±√(16 + 60)]/6
x = [-4 ±√76]/6
x = [-4 ±√(2^2 * 19)]/6
x = [-4 ±2√19]/6
x = [-2 ±√19]/3
x = [-2 + √19]/3
x = [-2 + 4.35]/3
x = 2.35/3
x = 0.78 (rounded to the nearest hundredth)
x = [-2 - ±√19]/3
x = [-2 - 4.35]/3
x = -6.35/3
x = -2.12 (rounded to the nearest hundredth)
<span>∴ x = -2.12 , 0.78 (rounded to the nearest hundredth)</span>
Substitution:
2x + (6(1/2x - 6)) = 19
2x + 3x - 36 = 19
5x - 36 = 19
+ 36
5x = 55
÷ 5
x = 11
y = (1/2 × 11) - 6
y = 5.5 - 6
y = -0.5
Elimination:
y = 1/2x - 6
- y
0 = 1/2x - 6 - y
+ 6
1/2x - y = 6
3x - 6y = 36
2x + 6y = 19
(add)
5x = 55
÷ 5
x = 11
y = (1/2 × 11) - 6
y = 5.5 - 6
y = -0.5
I hope this helps! Let me know if you need me to explain why I did some things :)
Answer:
m∠R = 39 degrees
Step-by-step explanation:
As complementary angles add up to 90 degrees, we can set up an equation to get x then find the measure of ∠R:
m∠R + m∠S = 90
2x+7+4x-13=90
6x+7-13=90
6x-6=90
6x=96
x=16
Since m∠R = (2x+7), 2x+7 would be 2(16)+7 or 39 degrees. So in conclusion, m∠R = 39 degrees
Answer:
Area = 370 m²
Cost to paint = £105
Step-by-step explanation:
Area of the wall of a cinema hall = Area of a trapezoid (1)+ Area of a rectangle (2) + Area of a trapezoid (3)
Area of a trapezoid = 
where 
and 
are the parallel sides and h is the distance between these sides.
Area of trapezoid (1) = 
= 69 m²
Area of the rectangle (2) = Length × Width
= 12 × 15
= 180 m²
Area of the trapezoid (3) = 
= 121 m²
Now area of the wall = 69 + 180 + 121
= 370 m²
One tin covers the area = 25 m²
Number of tins required to paint the wall = 
= 
= 14.8
Therefore, number of tins to be purchased = 15
Cost to paint the complete wall = 15 × £7
= £105
