Every time i change `minSDKVersion` from `build.grade` from 8 to 9
i get that `R error` 

I checked every single solution been mentioned here

["cannot resolve symbol R" in Android Studio](https://stackoverflow.com/questions/17054000/cannot-resolve-symbol-r-in-android-studio)

without fixing it 

beside I cant keep `minSDKVersion` to 8 as many things just don`t work with 8 

my gradle 

```
apply plugin: 'com.android.application'

android {
compileSdkVersion 22
buildToolsVersion "22.0.1"
defaultConfig {
    applicationId "com.kareem.droid1"
    minSdkVersion 9
    targetSdkVersion 22
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
productFlavors {
}
}

dependencies {
compile 'com.google.android.gms:play-services-ads:7.3.0'
}

```

how to solve it ?

thanks for help