va rog 6,7,10 dau coroană
Răspunsuri la întrebare
Răspuns:
6)a) a=3√2+6√3
b= 5√2-3√3
c=-8√2-3√3
a+b+c=(3√2+6√3)+(5√2-3√3)+(-8√2-3√3)=3√2+6√3+5√2-3√3-8√2-3√3
a+b+c=3√2+5√2-8√2+6√3-3√3-3√3=0∈Z
b) a= 3-2√7
b=3√7+1
c=-√7-1
a+b+c=(3-2√7)+(3√7+1)+(-√7-1)=3-2√7+3√7+1-√7-1=-2√7+3√7-√7+3+1-1=√7-√7+3=0+3=3∈Z
c) a= -2√6+5√2
b=9√2-4√6
c=6√6-14√2
a+b+c=(-2√6+5√2)+(9√2-4√6)+(6√6-14√2)=-2√6+5√2+9√2-4√6+6√6-14√2=-2√6-4√6+6√6+9√2+5√2-14√2= -6√6+6√6+14√2-14√2=0∈Z
d) a=12-√7
b=3√7+3
c= -2√7+1
a+b+c=(12-√7)+(3√7+3)+(-2√7+1)=12-√7+3√7+3-2√7+1=-√7+3√7-2√7+12+3+1=2√7-2√7+16=0+16=16∈Z
7) a) 2√3+5√3-(7√3+2√3)=7√3-9√3= -2√3
b)11√7+7√7-(3√7-5√7)=18√7-(-2√7)=18√7+2√7=20√7
c) 2√5-4√5+(2√5+9√5-7√5)= -2√5+4√5=2√5
d) √5+(-3√5+6√5)-(-3√5-9√5)=√5+3√5-(-12√5)=4√5+12√5=16√5
e)2√6+3√3-(5√6-3√3)+(-3√6-9√3)=2√6+3√3-5√6+3√3-3√6-9√3=2√6-5√6-3√6+3√3+3√3-9√3=-6√6-3√3
f)(-9√13+5√13)-(8√13-√13)+7√11=-4√13-7√13+7√11=-11√13+7√11
g)(3√2-2√3)+(-4√2-3√3)-(6√2-5√3)=3√2-2√3-4√2-3√3-6√2+5√3=3√2-4√2-6√2-2√3-3√3+5√3=-7√2-5√3+5√3=-7√2
Explicație pas cu pas:
Răspuns:
Explicație pas cu pas:
a)
3√2+6√3+5√2-3√3-8√2-3√3
=se reduc toate (le tai pe toate)
=0
-
b)
3-2√7+3√7+1-√7-1
=se reduc -2√7 ...3√7...- √7......+1 ...-1
=3
-
c)
-2√6+5√2+9√2-4√6+6√6-14√2
=se reduc toate
=0
-
d)
12-√7+3√7+3-2√7+1
= se reduc....-√7 ....+3√7 ....-2√7
=12+1
= 13
-
-
7)
a)
=2√3+5√3-7√3-2√3
=7√3-7√3-2√3
=se reduc....7√3 ...-7√3
= -2√3
-
b)
=11√7+7√7-3√7+5√7
=18√7+5√7-3√7
=23√7-3√7
=20√7
-
c)
=2√5-4√5+2√5+9√5-7√5
=-2√5+2√5+9√5-7√5
= se reduc ...- 2√5 ....+2√5
=9√5-7√5
= 2√5
-
d)
=√5-3√5+6√5+3√5+9√5
=-2√5+6√5+3√5+9√5
=4√5+3√5+9√5
=7√5+9√5
=16√5
-
e)
=2√6+3√3-5√6+3√3-3√6-9√3
=2√6-5√6-3√6+3√3+3√3-9√3
=-3√6-3√6+6√3-9√3
=-6√6-3√3
=-3*(2√6-√3)
-
f)
=-9√13+5√13-8√13+√13+7√11
=-4√13-8√13+√13+7√11
=-12√13+√13+7√11
= - 11√13+7√11
-
g)
=3√2-2√3-4√2-3√3-6√2+5√3
=3√2-4√2-6√2-2√3-3√3+5√3
=-√2-6√2-5√3+5√3
=se reduc -5√3....+5√3
=-7√2
-
10)
a)
√8+√18-√32
=2√2+3√2-4√2
= 5√2-4√2
=√2
-
b)
√45+√20-√125
=3√5+2√5-5√5
=5√5-5√5
=0
-
c)
√27+√243+√75-√108
=3√3+9√3+5√3-6√3
=11√3
-
d)
√72-√98+√128
=6√2-7√2+8√2
=-√2+8√2
=7√2