Question

using
${x}^{2} + (a + b)x + ab$
$(1)9.7 \times 9.8$
please answer in brief i will mark as brainlist

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Answer 1

Answer:

82.91

Step-by-step explanation:

by the formula

$(x + a)(x + a) = {x}^{2} + x(a + b) + ab$

$9.7 \times 9.8$

$(9 + 0.7)(9 + 0.8)$

${9}^{2} + 9(0.7 + 0.8) + (0.7 \times 0.8)$

$81 + 9(.15) + .56$

$81 + 1.35 + 0.56$

$82.91$