Answer:
x = 3 or -7
Step-by-step explanation:
Recall that for a quadratic equation in the form:
Ax² + Bx = C
we need to add (B/2)² to both sides of the equation to
In our case, we are given:
x² + 4x = 21
compared to the general equation above, B = 4, hence we need to add (4/2)² to both sides
x² + 4x = 21 (complete the square)
x² + 4x + (4/2)² = 21 + (4/2)²
x² + 4x + 2² = 21 + 2²
(x+ 2)² = 21 + 4
(x+ 2)² = 25 (take square root of both sides)
(x+2) = ±√25
(x+2) = ±5
hence
(x+2) = +5----> x = 5 - 2 = 3 (answer)
or
(x+2) = -5 ----> x = -5 - 2 = -7(answer)
Answer:
Sum he wasn't suupposed to be doing....... ;-;
Step-by-step explanation:
For a given line and a point outside of it, only one plane passes through both of these.
<h3>
How many planes can be defined with one line and one point outside?</h3>
By definition, we say that a plane is defined by 3 non-colinear points.
With 3 non-colinear points we can make a line and a point outside of that line.
So, in resume, any plane can be defined by a line and a point outside of it. Then, with a line and a point outside of it we can define a single plane. This means that if we have a line and a point outside of the line, only a single plane passes through both of them.
So the correct option is C: one.
If you want to learn more about planes:
brainly.com/question/1655368
#SPJ1
Answer:
The third angle of the triangle is 70°.
Step-by-step explanation:
The two angles of a triangle (say Δ ABC) are given to be 30° and 80°.
We have to find the third angle.
Let us assume that ∠ A = 30° and ∠ B = 80°, then we have to find ∠ C.
Now, we know that, ∠ A + ∠ B + ∠ C = 180° {Property of a triangle}
⇒ 30° + 80° + ∠ C = 180°
⇒ ∠ C = 180° - 30° - 80° = 70°
Therefore, the third angle of the triangle is 70°. (Answer)
y = kx is the formula for direct variation
8 = k*20
divide by 20
8/20 =k
divide by 4
2/5 =k
y = 2/5 x
formula: y = 2/5x
b) y=2/5x
y = 2/5 *7
y = 14/5
or as a mixed number 2 4/5
