1 = 2
2 = 6
3 = 12
4 = 20
5 = 30
6 = 42
7 = 56
Vậy 9 = ? mấy
2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48=??
nhanh mk tk, đưg quên kb vs mk nha
nếu 2=6
3=12
4=20
5=30
6=42
thì 9=?
12+12+12+....=42
tìm y biết 42-yx3=30
78 + 12 - 42 = x - 12
x là mấy
Tìm x, biết:
a/ x + 37 = 73
b/ 42 - x = 30
Tính:
a)\(\frac{38}{42}+\frac{84}{42}=\) b)\(\frac{12}{36}+\frac{56}{12}=\)
c)\(\frac{81}{24}+\frac{98}{42}=\) d)\(\frac{87}{99}+\frac{98}{99}=\)
42+64+71+10+30=
25+14+36+48+46=