2(x^2+5)=60 to 2x^2+10=60 distributive property (a(b+c)=ab+ac)
2x^2+10=60 to 2x^2=50 property of equality or something like thht (a=a and b=b, so a-b=a-b) and also addative inverse (a+-a=0) (added -10 to both sides)
2x^2=50 to x^2=25 propery of euality and multiplicative inverse (a times 1/a=1) and one produce property (1 times a=a)
x^2=25 to x=+/-5 property of equality and something else