Answer:
Step-by-step explanation:
1). x² - 10x + a²
By using the formula of (a - b)² = a² - 2ab + b²
x² - 2(5)x + a²
Therefore, for a perfect square of the expression a should be equal to 5.
Therefore, (x² - 10x + 25) will be the answer.
2). x² + 2ax + 36
= x² + 2(a)x + 6²
For a perfect square of the given expression value of a should be 6.
x² + 2(a)x + 6² = x² + 2(6)x + 6²
= (x + 6)²
Therefore, x² + 12x + 36 will be the answer.
3). 
To make this expression a perfect square,
a² = 
= 
Therefore, the missing number will be 
.
Answer:
r1= -10 r2= +10 (10)
Step-by-step explanation:
r²= 165-65
r²= 100
r=+-(root)100
r1= -10
r2= +10 (10)
Answer:
Step-by-step explanation:
Area of triangle = 1/2 * base * height
Use the side of length 5.6cm as base, the height will be a perpendicular line from the base to the tip of the triangle.
From the right-angle triangle formed by the height and the side of length 3.9cm,
sin(56°45') = height / 3.9
height = 3.9*sin(56°45')
Substituting back into the area equation:
Area = 1/2*5.6*3.9*sin(56°45')
= 9.0cm^2
= 9cm^2
+ 15 because you solve negative inside but when you get it out it becomes positive
