If you are solving for x then here’s how:
(3x2 + 4x - 12) = (x + 5)
Remove the x on the left by remove one x from both of the sides.
(3x2 + 3x - 12) = 5
Add 12 onto both sides
(3x2 + 3x) = 17
Multiply
(6 + 3x) = 17
Take away 6 from both sides
3x = 11
Divide by 3 on both sides
x = 3.666 recurring
If segment AB is perpendicular to segment CD, then a right angle (90°) is formed.
7x + 27 = 90
7x = 63
x = 9
Answer:
3 metres
Step-by-step explanation:
If we draw this out, we'll see that there are actually two similar right triangles (see attachment), which means that we can set up a proportion.
The height of the lookout tower corresponds to the height of the wooden column, while the shadow of the lookout tower corresponds to the shadow of the wooden column. We can then write:
(height of lookout tower) / (shadow of tower) = (height of column) / (shadow of column)
16 / 12 = 4 / x , where x is the shadow / unknown we want to find
Cross-multiply:
16x = 48
x = 3
The answer is thus 3 metres.