5. a^2 + b^2 = c^2...where a and b are the legs and c is the hypotenuse
7^2 + 10^2 = c^2
49 + 100 =c^2
149 = c^2....take square root of both sides, eliminating the ^2
sq rt 149 = c
12.21 = c.....so the approximate length of 3rd side is 12 m
6. x = number of books bought
7. m < 2 + m < 8 = 180
8. 1000 = 400 + 24x
1000 - 400 = 24x
600 = 24x
600/24 = x
25 = x <=== 25 months he will have spent $ 1000
y = -3(x<span> - 2)^2 + 1 </span>x<span>-coordinate of vertex: </span>x<span> = -b/(2a) = -12/-6 = 2 y-coordintae of vertex: y(2) = -12 + 24 - 11 = 1 </span>Vertex form: y = -3(x<span> - 2)^2 + 1 Check. Develop y to get back to standard form: y = -3(</span>x^2 - 4x + 4) + 1 = -3x<span>^2 + </span>12x<span> - </span>11<span>. </span>
I think the best option is 24.
Answer: <span>2x² + x - 2 (the first option)</span>