Answer:
Chris is 8 years old
Step-by-step explanation:
If you add the ratio together, it becomes 7
Divide 56/7 -> 8
1*8=8
Chris is 8
<span> Molecules comprised of main group elements adopt the structure that minimizes the repulsions between bond pairs (bp) of e⁻s and lone pairs (lp) of e⁻s (VSEPR theory: Wikipedia). However lp are only attracted to one +ve nucleus and consequently are more diffuse (spread out) and hence in terms of e⁻↔ e⁻ repulsion: lp-lp>lp-bp>bp-bp. So we have: CH4 AX4 regular tetrahedron angles all 109.5°; NH3 trigonal pyramidal AX3E the lone pair squeezes the H-N-H angles to <109.5° (~108°); for H2O: AX2E2 V shaped or bent - now we have lp-lp repulsion the H-O-H closes to significantly less than 109.5° (~104°).
hope this helps</span>
-9x(5 - 2x) Distribute/multiply 9x into (5 - 2x)
(-9x)5 - (-9x)2x
-45x - (-18x²) 2 negative signs cancel each other out and become +
-45x + 18x² Your answer is A ( the first option)
