Option 1 : -22
using formula
(a + b )(a - b ) = a^2 - b^2
(√10 + 2√8) (√10 - 2√8)
= (√10)^2 - (2√8)^2
= 10 - 2×2×8=10-32
= -22
2nd question answer is option 3
Answer:
x = 2 + sqrt(5) or x = 2 - sqrt(5)
Step-by-step explanation using the quadratic formula:
Solve for x over the real numbers:
7 (x^2 - 4 x - 1) = 0
Divide both sides by 7:
x^2 - 4 x - 1 = 0
Add 1 to both sides:
x^2 - 4 x = 1
Add 4 to both sides:
x^2 - 4 x + 4 = 5
Write the left hand side as a square:
(x - 2)^2 = 5
Take the square root of both sides:
x - 2 = sqrt(5) or x - 2 = -sqrt(5)
Add 2 to both sides:
x = 2 + sqrt(5) or x - 2 = -sqrt(5)
Add 2 to both sides:
Answer: x = 2 + sqrt(5) or x = 2 - sqrt(5)
Answer:
30-5×2 of 3+(19-3) ÷8
Step-by-step explanation:
30-5×6+(19-3)÷8
30-5×6+16÷8
30-30+8
38-30
8
Answer:
D
Step-by-step explanation:
The equation of a line in point- slope form is
y - b = m(x - a)
where m is the slope and (a, b) a point on the line
here m = - 6 and (a, b) = (- 9, - 3), so
y - (- 3) = - 6(x - (- 9)), that is
y + 3 = - 6(x + 9)
