Question

31.7 помогите пожайлуста

Answer 1

$1) {b}^{2} - 25 - {b}^{2} = - 25$
$2) {c}^{2} + 81 - {c}^{2} = 81$
$3) frac{1}{9} - {z}^{2} - frac{1}{9} = - {z}^{2}$
$4) - frac{14}{69} + frac{16}{49} - {d}^{2} = - {d}^{2}$
$5)0.81 - {a}^{2} - a - {a}^{2} = \ 0.81 - 2 {a}^{2} - a$
$6)5k - {k}^{2} + {k}^{2} - 1.44 = \ 5k - 1.44$