## anonymous one year ago What is the value of Fraction 1 over 2x3 + 3.4y when x = 3 and y = 4?

1. Michele_Laino

hint: $\Large \frac{1}{{2{x^3} + 3.4y}} \to \frac{1}{{2 \times \left( {{2^3}} \right) + \left( {3.4 \times 4} \right)}} = ...?$

2. anonymous

25.6?

3. anonymous

@Michele_Laino

4. Michele_Laino

hint: $\frac{1}{{2 \times \left( {{2^3}} \right) + \left( {3.4 \times 4} \right)}} = \frac{1}{{16 + 13.6}} = \frac{1}{{29.6}} = ...?$

5. anonymous

@Michele_Laino im really bad at fractions but i think its 31.6?

6. Michele_Laino

it is: $\Large \frac{1}{{2 \times \left( {{2^3}} \right) + \left( {3.4 \times 4} \right)}} = \frac{1}{{16 + 13.6}} = \frac{1}{{29.6}} = 0.0338$ approximated value

7. Michele_Laino

$\large \frac{1}{{2 \times \left( {{2^3}} \right) + \left( {3.4 \times 4} \right)}} = \frac{1}{{16 + 13.6}} = \frac{1}{{29.6}} = 0.0338$

8. anonymous

these are the choices though 15.85 18.1 27.1 31.6

9. Michele_Laino

Sorry I have made an error since we have to substitute x=3 before Nevertheless, my expression above is wrong.

10. anonymous

oh

11. Michele_Laino

12. anonymous

|dw:1435768036043:dw|when x=3 and y=4

13. Michele_Laino

ok! then we have: $\frac{1}{2}{x^3} + 3.4y \to \frac{1}{2} \times {3^3} + 3.4 \times 4 = \frac{{27}}{2} + 13.6 = ...?$

14. anonymous

27.1

15. Michele_Laino

that's right!

16. anonymous

yay thank you (: @Michele_Laino

17. Michele_Laino

:)