2.4 * (10 + x) = 48

2.4 * (10 + x) = 48

2.4*(10+x)=48
10+x=20
x=20-10
x=-10

Two new operation symbols "*" and "&" are defined. The operation rules are: a * b = 3A, X & y = the square of X + the square of 2y-1, and the value of 3 * (2 & 5) is obtained

3*（2&5）
=3*3
=9

The meaning of a symbol △ is defined: a △ B = AB-1, 2 △ (- 3) and 2 △ [(- 3) - 5]

(1)2△(-3)=2×（-3）-1= -6-1= -7
（2）2△[(-3)-5]=2△（-8）=2×（-8）-1= -16-1= -17

The meaning of defining the operation symbol "*" is: a * b = a + B / AB (where a and B are not 0.)
A. Only (1) is correct
B. Only (2) is correct
C. (1) and (2) are correct
D (1) (2) are not correct
Which one do you want to choose~~~~~~
(1) the operation "*" satisfies the commutative law (2) the operation "*" satisfies the associative law
A * b = a + B / AB is actually a + B of ab

Choose a
Law of exchange:
a*b = (a+b)/ab
b*a = (b+a)/ba
a*b = b*a
satisfy
The law of association is not satisfied