(a+b)(a+c), getallen In onderstaande opgaven wordt ervan uitgegaan dat je de kwadraten van 1 tot en met tien kent en weet hoe je daaruit de kwadraten van de tientallen kunt bepalen!Bereken zonder rekenmachine:
1.
42
×
41
{\displaystyle {\ce {42\ \times \ 41}}}
2.
24
×
21
{\displaystyle {\ce {24\ \times \ 21}}}
3.
52
×
51
{\displaystyle {\ce {52\ \times \ 51}}}
4.
48
×
53
{\displaystyle {\ce {48\ \times \ 53}}}
5.
38
×
37
{\displaystyle {\ce {38\ \times \ 37}}}
6.
62
×
59
{\displaystyle {\ce {62\ \times \ 59}}}
7.
17
×
19
{\displaystyle {\ce {17\ \times \ 19}}}
8.
33
×
32
{\displaystyle {\ce {33\ \times \ 32}}}
9.
91
×
88
{\displaystyle {\ce {91\ \times \ 88}}}
(a+b)(a+c), wiskundig Schrijf onderstaande vermenigvuldigingen in de vorm van
a
⋅
x
2
+
b
⋅
x
+
c
{\displaystyle {\ce {a.x^{2}\ +\ b.x\ +\ c}}}
10.
(
a
+
r
)
×
(
a
+
s
)
{\displaystyle {\ce {(a\,+\,r)\ \times \ (a\,+\,s)}}}
a
2
+
(
r
+
s
)
⋅
a
+
r
⋅
s
{\displaystyle {\ce {a^{2}\ +\ (r\,+\,s).a\ +\ r.s}}}
11.
(
c
+
p
)
×
(
c
+
q
)
{\displaystyle {\ce {(c\,+\,p)\ \times \ (c\,+\,q)}}}
c
2
+
(
p
+
q
)
⋅
c
+
p
⋅
q
{\displaystyle {\ce {c^{2}\ +\ (p\,+\,q).c\ +\ p.q}}}
12.
(
m
+
n
)
×
(
m
−
l
)
{\displaystyle {\ce {(m\,+\,n)\ \times \ (m\,-\,l)}}}
m
2
+
(
n
−
l
)
⋅
a
−
n
⋅
l
{\displaystyle {\ce {m^{2}\ +\ (n\,-\,l).a\ -\ n.l}}}
13.
(
x
−
a
)
×
(
x
+
b
)
{\displaystyle {\ce {(x\,-\,a)\ \times \ (x\,+\,b)}}}
x
2
+
(
b
−
a
)
⋅
x
−
a
⋅
b
{\displaystyle {\ce {x^{2}\ +\ (b\,-\,a).x\ -\ a.b}}}
14.
(
a
+
2
r
)
×
(
a
+
s
)
{\displaystyle {\ce {(a\,+\,2r)\ \times \ (a\,+\,s)}}}
a
2
+
(
2
r
+
s
)
⋅
a
+
2
r
⋅
s
{\displaystyle {\ce {a^{2}\ + \ (2r \, + \, s).a \ + \ 2r.s}}}
15.
(
b
−
r
)
×
(
b
−
s
)
{\displaystyle {\ce {(b\,-\,r)\ \times \ (b\,-\,s)}}}
b
2
−
(
r
+
s
)
⋅
a
+
r
⋅
s
{\displaystyle {\ce {b^{2}\ -\ (r\,+\,s).a\ +\ r.s}}}
16.
(
g
+
2
r
)
×
(
g
+
3
s
)
{\displaystyle {\ce {(g\,+\,2r)\ \times \ (g\,+\,3s)}}}
g
2
+
(
2
r
+
3
s
)
⋅
a
+
6
⋅
r
⋅
s
{\displaystyle {\ce {g^{2}\ + \ (2r \, + \, 3s).a \ + \ 6.r.s}}}
17.
(
2
d
+
r
)
×
(
2
d
+
s
)
{\displaystyle {\ce {(2d\,+\,r)\ \times \ (2d\,+\,s)}}}
4
d
2
+
2
⋅
(
r
+
s
)
⋅
a
+
r
⋅
s
{\displaystyle {\ce {4d^{2}\ +\ 2.(r\,+\,s).a\ +\ r.s}}}
18.
(
2
q
+
7
r
)
×
(
9
q
+
2
s
)
{\displaystyle {\ce {(2q\,+\,7r)\ \times \ (9q\,+\,2s)}}}
18
q
2
+
(
7
r
+
2
s
)
⋅
a
+
14
⋅
r
⋅
s
{\displaystyle {\ce {18q^{2}\ + \ (7r \, + \, 2s).a \ + \ 14.r.s}}}
