Answer:
The first car was traveling 70 mph, while the second was driving 50 mph.
Step-by-step explanation:
Set the cars as a proportion:
X represents the speed of the second car. By cross multiplying, you get the following equation:
You solve by distributing 150 to get 210x = 150x + 3000.
Solving for x gets you 50.
That means the first car was going at 50 mph. Adding 20, you get 70 as the speed for the second car.
We know that
If the scalar product of two vectors<span> is zero, both vectors are </span><span>orthogonal
</span><span>A. (-2,5)
</span>(-2,5)*(1,5)-------> -2*1+5*5=23-----------> <span>are not orthogonal
</span><span>B. (10,-2)
</span>(10,-2)*(1,5)-------> 10*1-2*5=0-----------> are orthogonal
<span>C. (-1,-5)
</span>(-1,-5)*(1,5)-------> -1*1-5*5=-26-----------> are not orthogonal
<span>D. (-5,1)
</span>(-5,1)*(1,5)-------> -5*1+1*5=0-----------> are orthogonal
the answer is
B. (10,-2) and D. (-5,1) are orthogonal to (1,5)
Answer:
x = - 1 and x = 5
Step-by-step explanation:
Given
(x - 3)² + 2(x - 3) - 8 = 0
Let u = x - 3, then
u² + 2u - 8 = 0 ← solve for u
(u + 4)(u - 2) = 0 ← in factored form
Equate each factor to zero and solve for u
u + 4 = 0 ⇒ u = - 4
u - 2 = 0 ⇒ u = 2
Convert back to x, that is
x - 3 = - 4 ( add 3 to both sides ) ⇒ x = - 1
x - 3 = 2 ( add 3 to both sides ) ⇒ x = 5
