-30 is the answer to your problem.
Solution:
1. Move all terms to one side
<span>25{x}^{2}+40x+16-28=0</span>
2. Simplify <span>25{x}^{2}+40x+16-28 to <span>25<span>x<span><span>2</span><span></span></span></span>+40x</span></span><span><span>−12</span></span>
<span>25{x}^{2}+40x-12=0</span>
3. Apply the Quadratic Formula<span>x=\frac{-40+20\sqrt{7}}{50},\frac{-40-20\sqrt{7}}{50}
</span>
4. Simplify solutions
<span>x=-\frac{2(2-\sqrt{7})}{5},-\frac{2(2+\sqrt{7})}{5}</span>
Done!
Answer: after 3 days
Step-by-step explanation: Step-by-step explanation: The sister has to pay rent which is $60 which means she has negative $30 in three days the sister would have earned $60 and in 3 days the brother would have earned $60
Step-by-step explanation:
Since your question is incomplete, I have given you two different options based on your incomplete question.
Hope you understand this.
HAVE A GOOD DAY!