Answer:
1. d (last option)
2. a (first option)
Explanation:
Question 1
Rewrite
to make r the subject.
Subtract c from both sides:
![\implies b-c=\pi r^2](https://img.qammunity.org/2023/formulas/mathematics/college/cc694l836cs18r556rc53l27187a8idoay.png)
Divide both sides by
:
![\implies r^2=(b-c)/(\pi)](https://img.qammunity.org/2023/formulas/mathematics/college/c3qr4m0se20npeurl5sisv4xva6ieh1c1w.png)
Square root both sides:
![\implies r=\pm\sqrt{(b-c)/(\pi)}](https://img.qammunity.org/2023/formulas/mathematics/college/3cb2u2w2fgqixrqhkwyu30ilrbhhdk65n8.png)
Question 2
Rewrite
to make h the subject.
Square both sides:
![\implies d^2=(h)/(6.752)](https://img.qammunity.org/2023/formulas/mathematics/college/s8lpismfcsn97dyli3krnaopklbxusmt36.png)
Multiply both sides by 6.752:
![\implies h=6.752d^2](https://img.qammunity.org/2023/formulas/mathematics/college/hj29sj3bubzamjlbuh3y2p10cdiekehh0i.png)