9.7.1 Mat á stæðum með breytum

$-,b$

$-,(,-,5,),=,5$

$b^2$

${(-5)}^2,=,25$

$b^2,-,4,a,c$

${(-5)}^2,-,4,\left(,9,\right),(,-,2,),=,25,-,\left(,36,\right),(,-,2,),=,25,-,(,-,72,),=,25,+,72,=,97$

$-,b,\pm ,\sqrt{a}$

a. −14

b. 8

c. 2

d. 4

$-,(,-,5,),+,\sqrt{9},=,5,+,3,=,8,\text{og},-,(,-,5,),-,\sqrt{9},=,5,-,3,=,2$

Réttu svörin eru 2 og 8:

$-,(,-,5,),+,\sqrt{9},=,5,+,3,=,8,\text{og},-,(,-,5,),-,\sqrt{9},=,5,-,3,=,2$