Question

calculați va rog dau coroana urgent

Answer 1

S200=200×(200+1) supra 2=200×201 supra 2=40200÷2=20100

S300=300×(300+1)÷2=300×301÷2=90300÷2=45150

S100=100×(100+1)÷2=100×101÷2=10100÷2=5050

S302=302×(302+1)÷2=302×303÷2=91506÷2=45753

Answer 2

a)
$\frac{200 \times 201}{2} = 20.100$
b)
$3(1 + 2 + 3 + ... + 100)$
$3( \frac{100 \times 101}{2} ) = 15.150$
c)
$(1 + 2 + 3 + ... + 100) - (1 + 2 + ... + 21)$
$5.050 - \frac{21 \times 22}{2}$
$5.050 - 231 = 4.819$
d)
$1 + 2 + 3 + ... + 302 - (2 + 4 + ... + 302)$
$\frac{302 \times 303}{2} - 2( 1 + 2 + ... + 151)$
$45.753 - 2( \frac{151 \times 152}{2} )$
$45.753 - 22.952 = 22.801$

Coroniță plsss