Find the value of k for which the equation x² + k(2x + k – 1) + 2 = 0 has real and equal roots.

Which number completes the inequality? 2/3 < _ < 7/9

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )

Can someone, me with this.i really need with this